Protection
Forty-seven (23%) of the wild medicinal plant species discussed in this report were under some form of protection as of 1992. Fifteen of these (32%) are strictly protected and the use of 32 species (68%) is restricted (Table 2). Twenty-one additional medicinal plant species are protected and the use of 9 others is restricted, but these have not been gathered for commercial and industrial purposes in the last few years.
Estimation of the Medicinal Plant Resources
In characterizing the state of medicinal plant resources, it is necessary to analyze the degree of exploitation pressure and the quantities of plant materials that are taken from the natural habitats of the different species over definite periods of time. The quantities that can be gathered and initially processed in the country depend on two basic factors: the extent of the biological reserves and of the reserves being exploited for each species, and the need for the plant materials they supply.
We lack, for several reasons, well grounded scientific data about the reserves of available medicinal plants and the appropriate levels of exploitation for most of the species. Detailed reserve studies that have yielded actual results have been conducted on only a limited number of plants: Acorus calamus, Arcotostaphyllos uva-ursi, Ruta graveolens, Origanum vulgare ssp. hirtum. That is why, at this stage, an estimation of medicinal plant resources can only be performed with the help of data on the quantities of the plant resources gathered and bought between 1980 and 1990 in the Central Cooperative Union. A total of 182 active components of medicinal plants were annually purchased during this period. This does not include data on plant resources that were bought for only a year or two.
These active components may be classified in morphological terms as follows: Radices (roots), Rizomata (rootstock), Tubera (corms), and Bulbus (bulbs) - 31; Folia (leaves) - 30; Herbae (stems) - 73; Flores (blossoms and inflorences) -4; 2 Fructus (berries) - 13; Cortex (cortex) - 7; Semina (seeds) - 2; Diversae (other) - 3.
Table 2. Species Under Protection or Regulations Restricting Their Use
Species 1941 1961 1989 1991 In Red Book Protected Restricted Use Protected Restricted Use Protected Restricted Use Protected Restricted Use Acorus calamus L. - - - + - + - Actaea spicata L. - + - - - - - - - Adianthum capillus-veneris L. + - + - + - + - + Adonis vernalis L. - - - - - + - - - Aesculus hipocastanum L. - - + - - - - + + Alchemilla vulgaris complex - - - - - + - - - Alchemilla mollis (Buser) Rothm. - - - - + - + + + Alium ursinum L. - + - - - - - - - Alkanna tinctoria (L.) Tausch - + - - + - + - - Althaea officinalis L. - + - - - + - - - Anacamptis pyramidalis (L.) L.C. Rich. + - - - + - + + - Anagalis arvensis L. - + - - - - - - - Angelica pancici Vand. - - - - - + - - + Aquilegia nigricans Baumg. + - - - + - + + + Arctostaphyllos uva-ursi (L.)Spreng. - + - - + - + - + Artemisia alba Turra - - - - - - - + - Artemisia lerchiana Weber - - - - + - + - + Artemisia pontica L. - + - - - + - - + Artemisia santonicum L. - + - - - - - + - Asparagus officinalis L. - - - - - - - + - Asplenium trichomanes L. - - - - - + - + - Atropa bella-donna L. - + - - - + - + + Berberis vulgaris L. - - - - - + - + - Betonica officinalis L. - - - - - - - + - Bryonia alba L. - + - - - - - - - Calamintha officinalis L. - + - - - - - - - Calluna vulgaris (L.) Hull. - - - - - - + - + Carex arenaria - + - - - - - - - Carlina acanthifolia All. - + - - + + - + - Castanea sativa L. - - - - - - + - + Centaurium erythraea Rafn. - + - - - + - + - Cetraria islandica L. Ach. - - - - - - - + - Cnicus benedictus L. - + - - - + - + - Colchicum automnale L. - - - - - + - + - Convallaria majalis L. - + - - - + - + - Cystoseira barbata (Good.et Vood).Ag. - - - - - - - + - Cytisus nigricans - + - - - - - - - Daphne mesereum L. - + - - - - - - - Dictamnus albus L. - + - - - - - - - Digitalis lanata Ehrh. - + - - - - - - - Drosera rotundifolia L. + - - - + - + - + Dryopteris filix-mas (L.) Schott - + - - - - - - - Ephedra distachya L. + - - - + - + - - Eringium maritimum L. - + - - + - + - + Frangula alnus Mill. - + - - - + - + - Galanthus nivalis L. - - - - + - + - + Galega officialis L. - + - - - - - - - Gentiana asclepiadea L. - + - - - - - - - Gentiana cruciata L. - + - - - - - - - Gentiana lutea L. + - - + + - + - + Gentiana pneumonanthe L. - + - - - - - - - Gentiana punctata L. - + - + + - + - + Geum rivale L. - + - - - - - - - Glaucium flavum Crantz - - - - - + - + - Glycyrrhiza glabra L. - + + - + - + - + Gratiola officialis L. - + - - - - - - - Gypsophilla paniculata L. - + - - - + - + - Helichrysum arenarium (L.) Moench - - - - - + - + - Hepatica nobilis Mill. - + - - - + - + - Hyppophae rhamnoides L. + - + - + - + - - Hyosciamus niger L. - + - - - - - - - Hyssopus officialis L. + - - - - + - + - Ilex aquifolium L. + - + - + - + - + Inula helenium L. - + - - - + - + - Juniperus oxycedrus L. - - - - - + - + + Juniperus sabina L. - + + - + - + - + Lamium album L. - + - - - - - - - Leucojum aestivum L. - - - - - + - + + Lycopodium clavatum + - - - - - - - - Menianthes trifoliata L. + - - - + - + - + Nuphar luteum L. + - + - + - + - + Nymphaea alba L. + - + - + - + - + Orchis globosa L. - + - - + - + - + Orchis militaris L. - + + - + - + - + Orchis papilionaceae L. - + + - + - + - + Orchis provincialis Balb. - + - - + - + - + Orchis sp. - + - - - + + + Origanum vulgare L. ssp.hirtum - - - - - + - + - Paeonia peregrina Mill. - - - - - + - + - Paeonia tenuifolia L. - - - - + - + - + Periploca graeca L. + - - - - - - - - Phyllitis scolopendrium (L.) Newm. - + - - - + - + + Physalis alkekengi L. - + - - - - - - - Platanthera bifolia (L.) L.C.Rich. - + - - - - - - - Potentilla anserina L. - + - - - - - - - Pulsatilla halleri (All.) Wild. - - - - + - + - + Pulsatilla pratensis (L.) Mill. - + - - + - + - + Pulsatilla vernalis (L.) Mill. - - - - + - + - + Primula veris L. - + - - - - - + - Rhibes nigrum L. - - - - + - + - + Rheum raponticum L. + - - - + - + - + Rhodiola rosea L. - - + - - + - + - Rhubia tinctorum L. - - - - - + - + - Ruscus aculeatus L. - - - - - - - + - Ruta graveolens L. - + - - + - + - + Salvia tomentosa Mill. - - - - - + - + - Sedum acre L. - - - - - - - + - Sideritis scardica Griseb. - + - - + - + - + Taxus baccata L. + - + - + - + - + Valeriana officinalis L. - + - - - + - + - Verbascum pseudonobile Stoj. et Stef. - - - - - - - + + Vinca minor L. - - - - - + - + - Table 3 presents data about the average and extreme quantities of active components of medicinal plants gathered between 1980 and 1990. The table includes information about the number of years during which the gathering of specific active components was unrestricted in Bulgaria. The table also includes information about trends in the uses of medicinal plant materials (i.e., export, domestic, commercial, industrial uses, and uses in the food industry). This mechanism was used to meet greater demands for export and (to a lesser degree) in the domestic market.
In our analysis of this period, we avoided the problem of annual fluctuations by identifying six groups of active plant components, based on the average amount of plant materials gathered and bought:
Group 1 - quantities up to 1000 kg
Group 2 - quantities from 1000 to 5000 kg
Group 3 - quantities from 5000 to 10,000 kg
Group 4 - quantities from 10,000 to 50,000 kg
Group 5 - quantities from 50,000 to 100,000 kg
Group 6 - quantities above 100,000 kgGroup 1 includes 48 active plant components that are destined to meet the needs of the domestic market. The low average quantities reflect limited national reserves and, more rarely, low demand. Nine active components in this group are obtained from protected plants. It is interesting that some of them - Tubera Salep, Cortex Berberidis, Folium Meyanthidis, Folium Scolopendrii, Herba Asplenii - have on several occasions been opened to unrestricted gathering and still the quantities bought have been low. Though there is brisker demand for some of these plant resources, the capacities of the habitats where they occur do not allow for their use in quantities greater than the average for this period. The number of active components whose average quantities are influenced by limited demand or low purchase prices, independent of the export demand, is relatively high. Opportunities exist to gather these in higher average amounts.
Group 2 includes 52 active plant components. Many are sold through two or three outlets. Thirteen are taken from protected plants. Meeting the need for them is impossible given the present state of their populations. For species like Ruta graveoles, Frangula alnus, Althaea officinalis, and Origanum vulgare ssp. hirtum, the exploitation of natural reserves is unreasonable, since they can be successfully cultivated. Effective enforcement of restrictions on gathering is necessary for Primula veris, Betonica officinalis, Leucojum aestivum, Sedum acre, Carlina acanthifolia, and Colchicum automnale.
The third group includes 25 active plant components. They are taken in high average amounts due mainly to the fact that they are exported and supply only minimal quantities to the domestic market. Eight of the plants from which they are taken are protected. Continued use of these herbs will require, on the one hand, that they be successfully cultivated and, on the other, that exploitation of natural reserves be more limited than in the past (i.e., lower than the average quantities bought during the 1980-1990 period). After Arctostaphyllos uva-ursi was placed under protection, gathering was banned and effective control of its populations is now necessary. At the same time, this group also contains herbs derived from ruderal and weed species that can tolerate gathering beyond the average for this period.
Forty-four herbs are included in the fourth group, only four of which are obtained from protected plants. They are gathered in relatively large amounts, but restrictions on their gathering during the next few years is urgently needed.
Groups 5 and 6 include 8 and 6 active components respectively. As has been mentioned, some are cultivated while others have adequate reserves for their exploitation (Urtica dioica, Equisetum arvense, Artemisia absintrium). If properly used, the productive potential of these reserves can be maintained for a long period of time.
Table 3. Quantities of Medicinal Plant Active Components Gathered 1980-1990
Herbs
Legend: * = components produced from species under restricted usage regime
Average amount gathered and bought up from 1980-1990 Extreme quantities gathered and bought up Designated for unlimited gathering (# of years) Trading lines: Export Drugstores Pharmaceutical industry Food industry GROUP I - QUANTITIES BELOW 1,000 kg Tubera Salep * 116 382 7 - + - - Radix Artemisiae vulgaris 181 958 - - + - - Radix Bryoniae 98 455 - - + - - Radix Pimpinellae 129 341 - + + - - Radix Polypodii 97 352 7 - + - - Radix Sambuci ebuli 97 585 - - + - - Radix Saponariae 349 1,959 - - + + - Radix Tami communis 118 365 2 - + - - Cortex Berberidis * 178 576 4 - + - - Cortex Viburni 189 499 - - + - - Folium Convallariae * 146 394 - - - + - Folium Hederae 881 2,701 5 - - - - Folium Menyanthidis * 412 1,196 1 - + - - Folium Sambuci nigri 217 1,326 - - - - - Folium Scolopendrii * 80 250 2 - - - - Folium Syringae 343 1,881 - + + - - Folium Visci albi 877 4,941 3 + + - - Fructus Berberidis * 747 2,583 2 + + - - Fructus Ecballii 120 393 - - + - - Fructus Paliuri 773 3,697 - + + - - Semen Lithospermi 32 128 - + + - - Herba Achilleae clypeolatae 210 490 - - + - - Herba Aristolochiae 329 1,335 - + + - - Herba Artemisiae vulgaris 117 624 - - + - - Herba Asperulae 759 2,598 5 - + - - Herba Asplenii * 354 702 4 - + - - Herba Astragali glychyphylli 729 3,292 - - + - - Herba Cnici benedicti * 49 3,292 - - + - - Herba Cuscutae 78 78 - - + - - Herba Galeopsidis 79 702 - - + - - Herba Gallii aparini 286 1,755 - - + - - Herba Genistae tinctoriae 508 1,833 - - + - - Herba Hederae 174 498 1 - + - - Herba Linariae 769 5,651 - + + - - Herba Malvae 191 741 - - + - - Herba Menthae pulegium 150 1,444 - - + - - Herba Potentillae reptans 304 2,716 - - + - - Herba Saponariae 172 1,169 - - + + - Herba Tanaceti 343 1,858 - - + + - Herba Teucrii polii 509 1,755 - - + - - Herba Violae odoratae 117 285 2 - + - - Herba Urticae urensis 168 405 - - + - - Flos Althaeae * 431 2,365 - + + - - Flos Belidis 11 69 - - + - - Flos Crataegi 164 602 1 + + - - Flos Farfarae 70 590 - - + - - Flos Fillipendulae vulgaris 169 1,298 - + + - - Flos Onopordii 369 3,404 - - - + - Flos Rhoeados 205 706 1 - + - - GROUP II - QUANTITIES FROM 1,000 to 5,000 kg Radix Angelicae 2,984 12,309 1 - - - - Radix Bella-donnae * 4,505 15,541 1 - - - - Radix Betonicae 2,271 14,951 - + + - - Radix Bony-henrici 3,160 5,665 9 - + - - Radix Carlinae * 3,454 8,205 - + + - - Radix Genanii songuinei 1,525 4,961 - + + - - Radix Primulae * 2,156 5,823 - + + + - Radix Saponariae 349 1,959 2 - + + - Rhizoma Filicis-maris 1,377 6,293 - + - - - Rhizoma Hellebori 1,944 20,653 - - - - - Rhizoma Veratri 1,484 15,637 1 + - + - Cortex Betulae 2,078 3,832 1 + + - - Cortex Corylli 4,092 13,483 - - + - - Cortex Frangulae * 1,401 3,832 3 + - + - Folium Altheae * 4,799 12,419 - + + - - Folium Plantaginis lonceolatae 2,702 11,784 - + + - - Folium Plantaginis majoris 6,106 42,851 4 - - - - Folium Pulmonariae 4,938 12,326 2 + + - - Folium Stramonii 4,232 8,548 2 - - + - Folium Verbasci 4,475 16,055 - + - - - Fructus Alkekengi 1,170 2,628 2 + - - - Fructus Corni 1,579 3,127 - - + - - Fructus Myrthylli 1,026 3,917 3 + + + + Fructus Sambuci nigri 2,737 6,679 - + + - + Fructus Sorbi 1,276 3,585 3 + + - - Semen Colchici * 3,330 7,529 3 + - - - Herba Alchemillae * 2,768 5,291 4 + + - - Herba Artemisiae vulgaris 4,436 8,756 - - - + - Herba Asparagi * 1,251 13,328 - - + - - Herba Eryngii 1,150 3,035 - + + - - Herba Chelidonii 4,478 11,102 4 + + - - Herba Gentianae cruciatae 1,153 2,905 - - + - - Herba Fillipendulae 1,225 4117 - + + - - Herba Hieracii 1,899 5,698 6 + + - - Herba Leucoji * 1,632 9,056 - - - + - Herba Lithospermi 3,316 8,346 - + - - - Herba Myrthylli 3,003 18,840 - + + - - Herba Origani heracleotici * 4,899 12,126 1 - + - - Herba Polygoni avicularis 4,674 25,506 - + + - - Herba Polygoni hydropiperis 3,966 8,657 - - + - - Herba Rutae * 2,448 11,336 5 + + + - Herba Sedi acri * 1,332 5,755 - + + - - Herba Solidaginis 4,008 5,946 - - - - - Herba Stellariae 4,008 5,945 - + + - - Herba Urticae 2,635 7,477 - - + - - Flos Achilleae clypeolatae 1,457 4,527 - - + - - Flos Chamomilleae mund. 5,048 7,081 - - + + - Flos Cyani 3,801 8,784 - + + - - Flos Fillipendulae mund. 4,550 8,973 6 + - - - Flos Malvae 3,202 8,877 - + + - - Flos Paeoniae * 4,995 6,984 - + - - - Flos Verbasci 2,601 4,534 - - + - - GROUP III - QUANTITIES FROM 5,000 to 10,000 kg Radix Althaeae * 9,672 56,227 - + + - - Radix Cichorii 5,544 2,054 - + + - - Radix Inulae * 6,773 12,190 2 + + - - Radix Paeoniae * 6,747 25,888 - + - - - Folium Corrylli 5,987 30,552 2 + + - - Folium Fragariae vescae 6,156 2,575 2 + + - - Folium Lichen Cetrariae * 8,895 26,685 - + + - - Folium Myrthilli 7,059 24,563 2 + + + - Folium Salicis 7,624 41,431 1 + + - - Folium Uvae-ursi * 9,725 29,117 4 + + + - Herba Bella-donnae * 6,019 16,088 2 + - + - Herba Betonicae 6,806 26,919 - + + - - Herba Bursae pastoris 6,519 16,497 - + + - - Herba Cichoricae 6,801 37,942 - + + - - Herba Gallegae 7,900 28,968 1 + + - - Herba Herniariae 6,858 12,283 - + + - - Herba Hyperici 8,434 28,105 - + + - - Herba Leonuri 9,467 20,495 - + + + - Herba Melissae 6,078 23,809 - + + - - Herba Taraxaci 8,434 27,545 2 + - - - Herba Teucrii chamedris 8,936 23,824 1 + + + + Herba Violae odoratae 7,493 22,242 - + + - - Flos Primmulae * 6,916 14,089 9 + + - - Flos Tiliae officinalis 6,900 15,878 5 + + - + Cystoseira barbata * 7,940 76,428 - + + + - GROUP IV - QUANTITIES FROM 10,000 to 50,000 kg Radix Althaeae mund. * 30,544 56,227 - + + + - Radix Bardanae 27,746 28,536 5 + + + - Radix Ononidis 39,884 82,246 6 + + + - Radix Rumici alpini 10,582 23,777 - + + + - Radix Taraxaci 18,182 40,427 8 + + + - Radix Urticae 46,499 72,778 2 + + + - Rhizoma Petasitidis 11,267 51,690 1 + - - - Cortex Fraxini 18,532 66,327 - + - + - Cortex Salicis 15,197 89,399 - + + - - Folium Bella-donnae * 13,470 27,423 3 + + + - Folium Betulae 45,579 72,934 2 + + - - Folium Cotyni 22,126 66,472 1 - + + - Folium Crataegi 35,612 137,751 2 + - - - Folium Malvae 13,694 36,261 4 + + - - Folium Rubiidaei 20,247 79,958 - + + - - Folium Rubi fruticosi 42,520 72,961 3 + + - - Folium Symphyti 12,303 22,269 2 + - - - Folium Tiliae 16,134 90,050 1 + - - - Folium Everniae 42,784 173,751 - + - - - Fructus Maly sylvestris 32,411 77,342 - + - - + Fructus Pruni spinosae 17,520 77,163 3 + - - - Herba Adonidis * 12,710 19,973 1 + + + - Herba Agrimoniae 13,100 44,501 - + + + - Herba Chamomillae 11,054 28,368 - + + + + Herba Euphrasiae 22,332 44,892 2 + + - - Herba Fumariae 20,135 55,719 3 + + - - Herba Marubi 17,497 90,978 - + + - - Herba Meliloti 15,267 50,998 2 + + + - Herba Millefoli 43,585 115,205 2 + + + - Herba Nasturcii 10,723 14,102 1 + + - - Herba Origani 11,233 25,968 4 - + - + Herba Saturejae montanae 12,575 57,970 - + + - - Herba Serpylli 40,891 111,930 2 + + + + Herba Tribulix terrestris 30,888 162,958 - - - - - Herba Verbenae 10,524 38,203 1 + + - - Herba Veronicae 43,052 75,819 3 + + - - Herba Vincae minoris * 11,819 44,125 9 - + + - Herba Visci albi 34,724 102,071 1 + + - - Folia Farfarae 22,958 42,223 - + + + - Flos Consolidae 13,328 35,526 4 + - - - Flos Millefoli 18,331 34,371 - + + - - Flos Sambuci nigri 11,401 16,138 6 + - + - Flos Sambuci mund. 16,175 31,566 7 + + - - Flos Tanceti 37,362 77,136 - - + + - GROUP V - QUANTITIES FROM 50,000 to 100,000 kg Rhisoma Graminis 50,814 185,751 2 + + + - Rhizoma Valerianae * 81,163 148,059 7 + + + - Folium Mellissae 50,329 93,253 1 + + + + Fructus Crataegi 76,898 310,828 - + + + - Herba Equiseti 94,819 291,099 2 + + + - Herba Hyperici 56,919 145,513 3 + + + - Herba Urtici mundatae 77,113 219,972 - + - - + Flos Crataegi cum folia 76,898 310,828 4 + + + - GROUP VI - QUANTITIES OVER 100,000 kg Folia Urticae 316,469 378,809 2 + + + - Fructus Rosae 1,146,018 22,329,371 - + + + - Fructus Sambuci ebuli 272,596 1,272,898 - + - - + Herba Absinthii 109,196 228,977 - + + + + Flos Chamomillae 136,321 248,600 - + + + + Flos Tilliae 162,955 270,867 8 + + - + Management of the Medicinal Plant Resources in Bulgaria
The purposeful use of medicinal plant resources in Bulgaria, and the collection of their active components in industrial quantities, began after World War I, mainly in response to the demand for them in Germany. During the 1930s collecting developed more and more actively, and the export of plant medicinal materials became the main factor influencing the scale (i.e., number of species and quantities) of this activity. The increase in scale is well illustrated by the data on the amount of herbs exported. In 1934, 8244 kg were exported; by 1939 this had increased some 8700% to 721,000 kg.
Until 1947 the picking, purchasing, processing, and selling of the herbs was organized by a small number of private firms and cooperatives. This structure remained unchanged until the political and economic changes in Bulgaria after 1944 took place. For a short time (1947-1955) the government monopoly on gathering, buying, cultivating, and processing of the medicinal and aromatic plants was held by the National Pharmaceutic Administration - the "Department of Medicinal Plants."
In 1955 the monopoly was given to the Central Cooperative Union and its branches: the consumer cooperatives, the cooperative unions, and the specialized enterprise "Bilkocoop." This administrative structure functioned actively until 1990, when the government's monopoly was broken up. The "Bilkocoop" cooperative carried out the main part of these activities. It oversaw the whole process of organizing, governing, and monitoring the gathering and production of herbs. These functions encompassed such basic tasks as: studying the demands of the domestic and foreign market; working out annual plans for gathering and buying medicinal plant materials from the herb-gathering regions and for processing the materials; production of saplings for the cultivated medicinal plants; and so forth.
The other functional units of the Central Cooperative Union were the Cooperative Unions and the Consumer Cooperatives. The Cooperative Unions organized the allocating and marketing of the medicinal plant materials that were bought and processed by the Consumer Cooperatives in the corresponding region. The boundaries of the herb-gathering regions matched the boundaries of the administrative regions. The Cooperative Unions had central stores where the herbs were collected, baled, and packed in conventional wrapping. Through a system of regular and in-terim control posts, the Consumer Cooperatives dealt with the buying and initial processing of the plant materials. The gathering of the materials from the natural habitats was performed by herb-gatherers (either as individuals or in teams).
Beyond the Central Cooperative Union and its departments, the departments of the Committee of Forests (or, as it was formerly known, the Committee for Forestry and Forestry Industry) and the separate chemical and pharmaceutic enterprises also played roles in the management of medicinal plant resources. The organization of labor and the functional links between the separate branches were analogous to those of the main structure.
In addition to exploiting the natural reserves, these branches and departments organized different activities connected with the preservation of the medicinal plants in the separate regions and in the country as a whole. It was with their help (mainly through the efforts of the "Bilkocoop" Cooperative) that the mapping of the medicinal plants in Bulgaria, studies of the state of the resources, and explorations of the potential for cultivating the rare and threatened medicinal species were able to begin.
Due to the lack of funds, results of these studies were obtained for only a limited number of species, and the "Chorological Atlas of the Medicinal Plants in Bulgaria" is still awaiting printing. This is why the chorological and ecological details of many plants from the Bulgarian flora, as well as the potential for restoration of the exploited species, were not taken into consideration in the past. As a result, great quantities of biomass were removed every year from the same habitats, which in turn led to the overexploitation of many valuable medicinal species.
The biologically inexpedient exploitation of medicinal plant resources has continued in our country even after the adoption of a free market economy. In addition to the existing structures of the CCU and the Committee of Forests, mentioned above, a great many private firms have actively joined in the gathering, buying, and marketing of plant materials. Thus, for a variety of reasons, the possibilities for managing the functions of all sectors (private, state, and cooperative) have been seriously diminished.
Anthropogenic Impacts on Medicinal Plant Resources
The economic exploitation of wild medicinal plants affects the state of their natural reserves and their reproductive capacities. The stress of continuous exploitation makes them vulnerable to different aspects of human activity, which on the whole have had negative results.
The greatest impacts are from industrialization, urbanization, road construction, and the accumulation of industrial and transportation-related waste products. These activities destroy medicinal plant habitats. Soil pollution - a result of the inappropriate exploitation of soils - and the introduction of chemicals in farming operations are other factors aggravating habitat conditions. The application of artificial fertilizers and chemicals for crop protection affects a large group of medicinal plants whose natural zones of distribution are the plains and mountain foothills - regions that are intensively farmed. These medicinal plants are mostly anthropophytic - weed and ruderal species such as Papaver rhoeas, Centaurea cyanus, and Sambucus ebulus.
The sharp change in ecological conditions caused by logging, fires, the plowing of natural herbaceous plant communities, and alterations in the hydrological regime of habitats has the most grievous consequences for the plants. The populations of many hydrophytic species (Leucojum aestivum, Acorus calamus, Menianthes trifoliata, Mentha sp., Orchis sp.) were seriously affected by the drainage of swampy and marshy regions along the large rivers (the Danube, Maritsa, and Tundzha), along the Black Sea coast, and in the central parts of the country over the last several decades. Some of these plants are entirely extinct, while others have lost their significance as sources of industrial quantities of medicinal agents.
Changes in the original vegetation as a result of irregular silvicultural activities - especially wholesale and partial logging and the creation of coniferous monocultures, often using species alien to the natural flora of the country - have had consequences that are both negative and long-lasting. The violation of the structure of the communities leads to their decline in terms of both quantity and quality, affecting the medicinal plants within them.
Afforestation of non-forest regions and plowing and cultivating of plains and pastures radically change the habitat conditions for the medicinal plants in these areas, whose populations then either diminish or disappear completely.
Excessive grazing also affects the composition and reproduction of medicinal plants. At present, medicinal forb species are either growing fewer in number or disappearing from pastures, while the presence of ruderal species is increasing.
Mass tourism, ski resorts, and construction in the mountains, with all their negative consequences, influence the phytocenoses and their medicinal plant constituents.
The reserves of medicinal plant resources are also strongly affected by the way their habitats are exploited. One basic reason behind their decline is disturbance to the reproductive potential of the populations. Reproductive potential depends on two factors: the specific biological features of the individual species and the type and quantity of active plant components gathered. The wrong manner of gathering, the lack of a restoration period, the exhaustion of the populations, damage to normal sexual and vegetative reproduction - all can lead to the reduced capacity of natural habitats to serve as reserves. To address this problem, traditional herb gathering practices, with their characteristic features of economic and social efficiency, will need to be combined with measures for the protection of the environment and its resources.
Legislation and Protectional Appraoch to the Preservation of Medicinal Plants
Historical analysis of the legislation indicates that the medicinal plants, in the period of their extensive application in folk medicine, were treated as part of the natural vegetation of the country and their use was subject to the general laws for environmental protection.
According to the 1936 law on national environmental protection (Official Gazette 59/1936), the Ministry of Agriculture and Public Property had the right "to ban forever or for a definite period of time the large-scale gathering of herbs and flowers from definite regions."
The increasing amount of wild medicinal plants gathered, mainly for export, made it necessary to prepare in 1941 a specialized Law on Medicinal and Aromatic Plants (Official Gazette 149/1941), and Regulations for the Application of the Law on Medicinal and Aromatic Plants (Official Gazette 20/1942). These acts regulated "the breeding, use, growing, distribution, and preservation of the herbs in the country," defined the rights and duties of those who were professionally engaged in this activity, and established the terms of reference of the different government institutions concerning use and protection, training of specialists, and the control of gathering. The objectives of these regulations were to create conditions and train specialists for the long-term use of the medicinal plants, to provide an occupation for part of the population, and to make Bulgarian herbs competitive on the foreign market.
The plants that came under the regulations of the law were listed and placed in several categories: plants the gathering of which was absolutely forbidden (15 species); plants that could be gathered up to a certain amount or within definite regions (6 species); plants that could be sold on the domestic market but were banned for export (42 species); and plants that could be gathered without restrictions (121 species). Herbs cultivated in Bulgaria and aromatic plants were listed separately. The protectionist approach is evident in the working out of this law: forbidden or restricted use is a prerequisite and necessary step toward the preservation of the medicinal plants and their reserves. Now, fifty years later, analysis of the list shows that all the fully protected species and more than half of those under restriction (including those whose export was banned and seven of the species listed for unrestricted gathering) are still either strictly protected or under a restricted use regime (Table 2).
The Law on Medicinal and Aromatic Plants remained in force until 1947. After that, the preservation and use of medicinal plants followed the texts of the general laws and acts (i.e., decrees, decisions, regulations). Thus, a biological resource that at the outset of its active exploitation was given both a biological and a socioeconomic appraisal and was protected with a specially created law, was later used rather inefficiently due to social and economic conditions.
After the 1960 Decree on National Environmental Protection (Izvestia 74/1960) was adopted, Order #761/1961 of the Principal Department of Woods gave protected status to 59 vascular species. Thirteen of these were medicinal plants. In addition, two other medicinal species were placed under a restricted use regime.
When the 1967 Law of Environmental Protection (Official Gazette 47/1967) was adopted, it became the basic act pertaining to the preservation of medicinal plants. The regulations of this law forbade "the gathering of herbs, forest berries, mushrooms, seeds, etc. in quantities and in a way that leads to their destruction or impedes their reproduction. Individual species of valuable herbs, berries, and other plant species are placed under a special management regime for their protection and cultivation." At present, the general responsibility for enforcement of this law rests with the Ministry of Environment. The Committee of Forests is responsible for the use of medicinal plants within the forest lands, which came under the regulations of the Law of Forests.
The "Basic Trends in the Protection, Cultivation, and Rational Use of the Medicinal Plants in the People's Republic of Bulgaria" played an important role among the acts regulating the protection and use of the major medicinal plant resources. They were enunciated by the State Council in 1977, and a special program was passed by the Council of Ministries (Resolution 193 27.X.1977) with a separate section on the "Protection and Enhancement of the Quality and the Quantity of the Medicinal Plant Resources." It assigned the major activities and duties to various state departments and public organizations that were directly or indirectly involved with the preservation of these resources. The coordinating functions were assigned to the Council on Medicinal Plants, an immediate subordinate to the Council of Ministries.
In 1987 the functions of this Council were devolved upon the National Centre for Phytotherapy and Folk Medicine, which after passage of Resolution #10 became responsible for official policy on the protection, cultivation, and rational use of the medicinal plants. The vague legal status of this body did not allow it to assume an effective oversight role. Nevertheless, with the active participation of this center, an act for the restricted use of medicinal plants was worked out by the Committee for Environmental Protection in 1989. It served as a basis for Regulation #719/1989 (Official Gazette 50/1989) of the Committee for Environmental Protection, which placed 31 medicinal plant species under restricted use. They were not totally excluded from economic use, but their annual rate of exploitation was strongly tied to the state of the habitats and the minimum demand for plant materials, mainly to meet the needs of the domestic market. The Ministry of Environment was assigned responsibility for controlling the use of medicinal plants placed under restriction.
A subsequent act, rescinding the previous one, was Regulation #973/1991 of the Ministry of Environment (Official Gazette 107/1991), which remains in force. It involves 41 wild medicinal plant species. Restrictions on the use of certain medicinal plants have been preserved. Economic uses of some cultivated species and species in need of strict protection have been banned. A three-year period has been designated for the cultivation of another 14 species, after which it will not be permitted to gather them from their natural habitats. At the end of the term, the restricted use regime will be reinstated only for those species whose biological peculiarities or ecological demands hinder their cultivation. The aims of this act are to enhance the interest of producers in cultivating medicinal plants and to meet the needs for active plant components from cultivated areas as a basic means of preserving these species.
As noted above, protection of medicinal plants in Bulgaria began in 1961, when 59 plant species, 13 of which were medicinal plants, were placed under protected status. Since 1989, the number of protected vascular species has been 330 under Regulation #718/1989 of the Committee for Environmental Protection (Official Gazette 56/1989). Twenty-nine of these are medicinal plants. This regulation bans the cutting, picking, gathering, eradication, and scientific collection of these species; destruction of their habitats; their transportation and selling abroad; and the gathering of their seeds, bulbs, and other reproductive parts. The use of a limited number of species is allowed for scientific research and for improved cultivation. Species rare in Bulgaria (Rheum raponticum, Glycyrrhiza glabra, Sideritis scardica, Ruta graveolens), species whose populations have reached critical levels as a result of continuous intensive exploitation (Gentiana punctata, G. lutea), or species whose habitats have been harmed by human economic activity (Acorus calamus, Orchis papilionaceae, O. militaris), as well as species whose populations propagate irregularly as a result of some biological or reproductive peculiarity (Arctostaphiyllos uva-ursi) are all placed under protection. Their use is entirely forbidden.
The restricted use regime, together with the strict protection of species and special habitats, are the main methods for preserving wild medicinal plants. The restricted use regime is adopted in order to improve habitat conditions for medicinal plants that are economically valuable but that are not found in economic quantities. It is comprised of rules for the use of natural habitats in a manner that protects them from exhaustion and destruction. It includes measures to monitor and control the state of the habitats and the natural quantities gathered, to enact occasional bans on exploitation in certain habitats, to control exports, etc.
In addition to their direct economic value, the medicinal plants are biologically valuable for the genetic information they contain (and which is concretely revealed in their economic qualities). The actual preservation of the genetic diversity of these species in their habitats is exercised through the different categories of protected areas. Protection may be granted to separate populations, plant communities, and complexes of ecosystems. The area of the protected areas ranges from several tenths of a hectare to thousands of hectares. The effectiveness of protection is proportional to the size of the territory; it is greatest in the natural reserves and national parks. The purposes of the protected areas are to preserve typical environmental conditions, to limit or (in some circumstances) even eliminate the human presence, and to minimize the anthropogenic influence.
The management regimen of protected areas may be rigid, with a total ban on any activity. In other categories of protected areas, only activities that may harm the populations may be banned (e.g., building, geological research, quarrying, changing of the hydrological regime, herb gathering, grazing, hunting). The genetic resources of the medicinal plants from protected areas may be used only as selection material or for a direct introduction into cultivated plants.
Beyond the reserves and national parks, medicinal plants are also preserved in 49 other protected areas (a total area of 817.5 ha) that were designated specifically to preserve the habitats of medicinal plants (Leucojum aestivum, Paeonia peregrina, Glycyrrhiza glabra, Galanthus nivalis, Juniperus communis, Sideritis taurica, Inula helenium, Primula veris). The exploitation of medicinal plants for economic purposes is forbidden in these areas, except for those created for the preservation of Leucojum aestivum. In these areas, not only the genetic resources but also economic resources are being protected. This mode of territorial protection, with a management regime consistent with the peculiarities of the plants and their most efficacious use and propagation, will probably become even more important in the future as a means of guaranteeing their steady long-term development.
The genetic resources of the medicinal plants are also preserved in specialized collections of live plants and seeds. One hundred and fifty-nine representatives of the Bulgarian flora are included in the live collection of medicinal plants in the Botanical Garden of the Bulgarian Academy of Sciences. Thirteen are under a special use regime and are partially exempt from gathering. The seeds of many of these species (78%) are offered for sale to different scientific organizations and botanical gardens through Delectus Seminum.
Another fact deserving of attention is the preparation and publication of the Bulgarian Red Data Book, which includes 38 medicinal species (out of 763 plants listed). It does not have the force of a regulation, but it is an expression of the public's ecological conscience and provides a basis for the active protection of the species included within it.
From this review of the legislative basis of, and approaches toward, environmental protection, we can draw the conclusion that under Bulgaria's present social and economic conditions it is impossible to use, monitor, or preserve effectively the medicinal plants on the basis of regulations. They do not possess the necessary range or power and cannot create an orderly system of organizing this traditional Bulgarian industry under the new economic situation. The medicinal plant resources occupy a special position in Bulgaria's economy. For that reason, there is an urgent need for a specialized law to direct their use and protection. The Ministry of Environment is working to develop such a law, which is expected to be taken up by the Council of Ministries in 1993.
Resources Development Forecast
Bearing in mind the general state of the medicinal plant resources, the present social and economic situation in Bulgaria, and the expectation that the specialized law for conserving medicinal plants will be soon passed, we can make an approximate forecast for the development of the resource.
During the next several years, the slow and general aggravation of the ecological state of the environment will continue, with all the attendant negative consequences for medicinal plant habitats. To some extent these consequences will be compensated for by the natural adaptive abilities of the populations, and it is possible to minimize them through appropriate measures so that they will not affect considerably the general economic resources of the habitats. The restitution of private arable lands and reconstruction of agriculture lie ahead. Restitution of forest lands is also being planned. In addition, the manner of exploitation of part of the lands will most probably change as well. Some meadows will be plowed, which will destroy the habitats of some medicinal plants.
After the restitution of the land to its owners, the interest in the cultivation of medicinal plants as a source of income for the population will increase. The exploitation of wild medicinal plants will probably decrease due to the greater efficiency offered by cultivation. However, it is necessary to stimulate this process by supplying the respective authorities with appropriate lands (mainly from the municipal and national forest funds), with information and technologies for cultivation, and with seeds and saplings. New technologies for the cultivation of rare and vulnerable species will relieve their habitats of economic exploitation and will enable their natural populations to propagate and expand. The wild populations will provide genetic material. The cultivated medicinal plants will also be the preferred source for the pharmaceutic industry due to their higher degree of homogeneity and their higher quality. The breaking up of the medicinal plant monopoly will attract investments and lead to increases in the production of remedies from plants.
The amount of the herbs consumed depends largely on the demand of the foreign market. The quality of Bulgarian medicinal plants is remarkable in terms both of the content of biologically active substances and their low prime cost. As a result there is a great demand for them on the foreign market. In the future, exports will probably amount to about 10,000 tons per year. The percentage of cultivated plants will increase as a result of growth in both the number of plants cultivated and the variety of plant materials produced.
Since the human conscience changes very slowly, the consumer attitude toward medicinal plants is most likely to remain intact for a long time to come. Unemployment turns many people with little ecological understanding and a lack of necessary knowledge and skills to the gathering of herbs. This process will gradually abate with the stabilization of the country's economy and with the passing of the civil legislation.
Measures for the Effective Preservation and Rational Use of Medicinal Plant Resources
The preservation and rational use of the medicinal plants requires a system of legislative, administrative, technological, educational, scientific, and other measures to maintain the balance between the activities of man and the ecological conditions for the development of these resources. These measures will secure not only the preservation but also the recovery and augmentation of the natural medicinal plant resources.
These measures concern mainly the medicinal plants under the restricted use regime and the species gathered in high quantities.
First, the preservation and the rational use of wild medicinal plants requires the mapping of the actual habitats of the species under greatest demand. The Chorological Atlas of the Medicinal Plants does not estimate the reserves of these species. Therefore, it is necessary to begin mapping procedures which gives priority to the most threatened and most heavily exploited species. The next stage must include studies of the state of their natural reserves and measurements of their areas, the materials in store, the state of their populations, and their capacity for exploitation. Studies of the ecological and biological peculiarities of the plants and their normal development will enable us to organize activities for the optimization and expansion of their habitats and reserves. This aspect is especially effective in the case of plants strongly affiliated with certain ecological conditions and hence difficult to cultivate. For some species, semi-cultural methods can be applied to their natural habitats.
One of the most effective ways of preserving natural reserves of valuable medicinal plants and of supplying the pharmaceutical industry with quality materials is the large-scale cultivation of wild plants, an area in which good work is already being done and good results have been achieved. The cultivation of the plants reveals the great advantages of this method: a homogeneous material is gathered from the cultivated areas, which ensures more efficient processing; mechanized growing and gathering of the active plant components is possible; only those populations, forms, and sorts highest in productivity are used, enhancing the profitability of the plants; and planning of the annual material yield is made possible. For these reasons, work along these lines must continue and expand. Regulation #973/1991 of the Ministry of Environment proposes the cultivation of another 11 medicinal species now under a restricted use regime by the end of 1994.
The adoption and observation of flexible laws to govern permissible exploitation, to allow for the periodic rest and recovery of habitats, and to set basic rules for gathering (consistent with the specific features of the individual species) is exceedingly important to the preservation and use of the medicinal plants. They need legal regulation.
A law should be passed that would regulate the use of and promote the preservation of medicinal plants in Bulgaria. Its most important features would be: definition of the requirements for qualified herb gatherers and herb merchants; creation of a governing system on all levels; improvement of the monitoring infrastructure; stimulation of the cultivation of wild medicinal plants; and establishment of a specialized fund for activities connected with the preservation of the genetic resources and natural reserves of medicinal plants.
These proposed measures will prove effective only if they are combined with a comprehensive educational program that improves the general state of ecological knowledge and promotes awareness of medicinal plants as a valuable and vulnerable natural resource.
Notes
1. The term "active components" (or "active plant components") is an approximate translation of the Bulgarian term "droga", which has no direct equivalent in English. It refers to the actual parts of the medicinal plants that are employed in treatments. The term "bilka", meaning "herb," is sometimes used as well, and is being adopted in the forthcoming new legislation on medicinal plant resources.
Bibliography
Aktarov, B. (Ed), 1939. Materials for Bulgarian Dictionary of Botany, Sofia, pp. 1-172.
Alexandrov, M., 1985. "Medicinal plants in Sakar mountains and their protection." In: Proc. Int. Symp. Project 8 MAB: Protection and conservation of the natural, territorial and genetic fund of Bulgaria, Blagoevgrad, vol. 3, pp. 89-95.
Alexiev, A., 1982. "An attempt for dynamic programming of plant populations for the purpose of nature resource management." In. Proc. Nat. Conf. Med. Plants, Sofia, p. 10.
Alexiev, A., 1982. "External principles in dynamic conservation of plant resources.." In: Proc. Nat. Conf. Environmental Protection and Reproduction, Nov. 105, Slanchev bryag, vol. T. pp. 289-293.
Andreev, N. et al., 1992. Identifier of higher plants in Bulgaria. Sofia, pp. 1-787.
Arnaudov, N., 1930. Medicinal and poisonous plants. Sofia.
Assenov, I., G. Ganchev, 1984. On the state of the Acorus calamus L. Habitats in Bulgaria and their conserva-tion. In: Savr. Theoret. I pril. Aspekti na rast. Ecol., vol. II, pp. 641-648.
Assenov, I., S. Nikolov, 1988. Pharmacognosy.
Astadjov, N., 1969. Studies on L. astivum L. from some natural habitats in the country. In: Proc. II Nat. Conf. Botany.
Boeva, A., L. Noninska, 1984. Spices as food and medicine.
Bondev, I., 1969. Edifiers and dominants in the vegetation cover of Bulgaria. In: Proc. II Nat. Conf. Botany. Sofia, pp. 199-212.
Bondev, I., 1991. The vegetation of Bulgaria.
Boychinov, A., P. Nikolov, P. Ikonomov, 1947. Medicinal plants. Sofia, pp. 1-238.
Chavdarov, I., R. Mehras, N. Peshevsky, 1982. Possibilities for accelerated reproduction of Leucojum aestrum L. I. In vitro reproduction of L. aestrum. In: Proc. Nat. Conf. Med. Plants.
Chavdarov, I., R. Mehras, N. Peshevsky, 1982. Possibilities for accelerated reproduction of Leucojum aestrum L. II. In vitro microreproduction of L. aestrum from different habitats. In: Savr. Theoret. I pril. Aspekti na rast. Ecol., vol. II, pp. 616-619.
Cherneva, J., E. Genova, 1984. Distribution and ecology of Melissa officinalis L. in Bulgaria. In: Savr. Theoret. I pril. Aspekti na rast. Ecol., vol II, pp. 651-655.
Cohen, N., M. Mladenov, I. Burov. Handbook of medicinal plant collection.
Dimkov, P., 1939. Guide to natural healing and living, Sofia.
Evstatieva, L., 1981. Studies of the biological characteristics of the species Thalictrum minus L., in view of the preparation of thalicarpinrich raw material. Doctoral thesis.
Evstatieva, L., 1982. Protection and reproduction of Acorus calamus as raw material for the pharmaceutical industry. In: Proc. Nat. Theoret. Conf. Environ. Protect. Reproduction, 1-5 November, Slanchev bryag, vol. 1, 313-318.
Evstatieva, L., 1983. Scientific problems of the rational use and conservation of medicinal plants. In: Proc. 3rd Nat. Conf. Botany. Sofia.
Evstatieva, L. 1984. Effect of some environmental factors on the growth and development of Acorus calamus L. In: Savr. Theoret. I. pril. Aspekti na rast. Ecol., vol. II, pp. 600-607.
Evstatieva, L. 1987. Introduction and perspective uses of Rhodiola rosea L. In: Jubil. Sborn. Nat. Conf. Biol., 1986.
Evstatieva, L and J. Yankulov, 1980. Biological characteristics of the species of genus Thalictrum L.: Specific features of the growth and development of Thalictrum minus L. Phytology, 14, 60-69.
Evstatieva, L., and N. Protich, 1981. Studies on the ecological and biological characteristics of Sideritis scardica Briseb. in culture. Tastenievadni nauki (Plant Science), 27(2):77-81.
Genova, E., 1982. Threatened medicinal plants and their protection. In: Proc. Nat. Conf. Med. Plants, Sofia, p. 23.
Genova, E., 1987. Some aspects of the studies of wild medicinal plants in Bulgaria. In: Proc. IV Nat. Conf. Bot., Sofia, vol. 2, pp 140-146.
Genova, E. and V. Russakaova, 1988. Techniques of preparation of raw Arctostaphylos uva-ursi (L) Spreng in disturbed communities. In: Proc. 10th Congress Dendrology, Sofia, 3-8 October, pp. 204-208.
Genova, E., V. Russakova, and J. Cherneva, 1987. Problems of the conservation and rational use of Arctostaphylos uva-ursi (L) Spreng in Bulgaria. In: Proc. IV Nat. Conf. Bot., Sofia, vol. 2, pp 124-131.
Genova, E., V. Russakova, and J. Cherneva, 1991. Phytocenologic and ecologic characteristics of Arctostaphylos uva-ursi (L) Spreng in some regions of Bulgaria. Phytology, 39:33-53.
Georgiev, G. and T. Kostova, 1980. Cultivation of medicinal plants. Sofia: Zemizdat.
Georgiev, G. and T. Kostova, 1982. Cultivation of medicinal plants in cultures. Sofia: Zemizdat. pp. 1-150.
Ikonomov, P., P. Nikolov, and A. Boychinov, 1947. Medicinal Plants, Sofia: Instruction for the protection of medicinal plants, 1989, Sofia, p. 21.
Ilieva, S. and E. Moynova, 1969. Biological features of Leucojum aestrium L. In: Proc. II Nat. Conf. Botany, pp. 65-71.
Issaev, I., I. Landjev and G. Neshev, 1977. Medicinal plants in Bulgaria and their use. Sofia: Zemizdat.
Ivancheva, S. and J. Yankulov, 1982. Introduction of Geranium sanguineum L. In: Proc. Nat. Conf. Med. Plants, Sofia, pp. 8-12.
Jordanov, D. (Ed), 1963. Flora of Bulgaria, vol I.. Sofia: Bulgarian Academy of Science, 507 pp.
Jordanov, D. (Ed), 1964. Flora of Bulgaria, vol II. Sofia: Bulgarian Academy of Science, 423 pp.
Jordanov, D. (Ed), 1966. Flora of Bulgaria, vol III. Sofia: Bulgarian Academy of Science, 637 pp.
Jordanov, D. (Ed), 1970. Flora of Bulgaria, vol IV. Sofia: Bulgarian Academy of Science, 748 pp.
Jordanov, D. (Ed), 1973. Flora of Bulgaria, vol V. Sofia: Bulgarian Academy of Science, 442 pp.
Jordanov, D. (Ed), 1976. Flora of Bulgaria, vol VI. Sofia: Bulgarian Academy of Science, 540 pp.
Jordanov, D. (Ed), 1979. Flora of Bulgaria, vol VII. Sofia: Bulgarian Academy of Science, 529 pp.
Jordanov, D. (Ed), 1982. Flora of Bulgaria, vol VIII. Sofia: Bulgarian Academy of Science, 518 pp.
Jordanov, D. (Ed), 1989. Flora of Bulgaria, vol IX. Sofia: Bulgarian Academy of Science, 539 pp.
Jordanov, D., S. Kozhuharov and N.Andreev, 1976. Mapping of the flora of Bulgaria and the issue of plan resources. Phytology, 4:3-15.
Jordanova, I. and S. Nikolov, 1984. Studies of the distribution of Glycyrrhiza glabra L. in the district of Russe. In: Savr. Theoret. I pril. Aspekti na rast. Ecol., vol. II, pp. 649-650.
Katov, A. and Z. Kostova, 1984. Dictionary of ecology and environmental protection.
Kitanov, B., 1986. Cultivated plants in Bulgaria. Sofia: Nauka I izkustvo, 322 pp.
Kitanov, B. and N. Stoyanov, 1960. Useful wild plants in Bulgaria. Sofia: Bulgarian Academy of Science, 482. pp.
Kozhuharov, S. and P. Andreev, 1980. Synopsis of the higher plants in Bulgaria. Sofia: Bulgarian Academy of Science.
Kumanov, B. et al (in press). Chorographic atlas of the medicinal plants in Bulgaria.
Kumanov, B., 1978. Mapping of medicinal plants in Bulgaria. In: Proc. Conf. Phytochemistry, phytochemical production and phytotherapy, pp. 1-10.
Kumanov, B. and A. Vitkova, 1978. Distribution of Ruta graveloens L. in Bulgaria. In: Proc. IV Nat. Conf. Botany, pp. 97-100.
Kumanov, B. and P. Peneva, 1989. Achievements and perspectives for the study, protection and rational use of medicinal plants in the IBBG of the Bulgarian Academy of Sciences. Phytology, 37:46-59.
Madjarova, D, N. Bigeva and M. Bubeva, 1980. Spice plants.
Mashlovsky, M. (Ed), 1989. State Pharmacopoeia USSR.
Mashlovsky, M., 1985. Medicinal Agents, Parts I and II.
Michev, B. et al., 1983. Wild forest fruits and berries as food and medicines.
Mitrev, A., M. Gavrilov and T. Tsakov, 1978. Mapping of the wild medicinal plants in Bulgaria and problems in their processing. In: Proc. Conf. Phytochemistry, phytochemical production and phytotherapy, pp. 1-13.
Mitrev, A. and S. Popova, 1982. Atlas of the medicinal plants in Bulgaria.
Muravieva, D., 1978. Pharmacognosy.
Neshev, G. and I. Landjev, 1989. Reference Guide to Medicinal Plants.
Nikolov, P., 1934/1935. Our folk cures. Ann. Rev. Sofia University, Medical Faculty, XIV.
One Hundred Curative Herbs, 1923. 1st edition. Bulgarian "Bilka" Publishing House.
Ovcharov, P. et al., 1992. Phytotherapy and folk medicine.
Ovcharov, P., 1990. Pharmacology and Toxicology.
Pavlov, K., 1950. Our Medicinal, Essential Oil and Spice Plants. Sofia.
Peneva, P., 1975. Studies of domestic and introduced varieties of medicinal chamomile. Rasten Nauki (Plant Science), 12(5):27-33.
Peneva, P., 1983. Study of the plant resources of Foeniculum vulgare. In: Proc. III Nat. Conf. Botany, Sofia, pp. 601-607.
Peneva, P, A. Krilov and S. Dimitrova, 1977. Effect of environmental conditions on the productivity of Foeniculum vulgare. Rasten. Nauki (Plant Science), 14(8).
Peneva, D. and T. Tsvetanova, 1983. Improvement of the genetic characteristics of medicinal chamomile. In: Proc. III Nat. Conf. Botany, Sofia, pp. 583-590.
Petkov, V. (Ed), 1982. Modern Phytotherapy.
Petrov, P. and D. Stoyanov, 1983. Inventory of the forest plant resources - sources of food and medicinal products, In: Proc. III Nat. Conf. Botany, Sofia, pp. 537-543.
Popova, S., 1984. On the taxonomy and mapping of medicinal plants. Gorsko stopanstvo (Forestry), 11:40-43.
Protich, N. and L. Evstatieva, 1988. Studies on four medicinal plant species with decorative value. Rasten. Nauki (Plant Science), XXV, 3:43-47.
Protich, N. and L. Evstatieva, 1989. Some biological characteristics of representatives of the Rheum genus. Rasten. Nauki (Plant Science) XXV, 5:46-50.
Shopalov, V., I. Dechev, and V. Pekhlivanov, 1989. Handbook on plant growing.
Shopalov, V, M. Gavrilov and J. Yankulov, 1983. Medicinal plants and their harvesting.
Staykov, V. et al, 1969. Essential Oil Plants, Sofia, pp. 194-195.
Staykov, V., 1955. On the distribution of Acorus calamus in Bulgaria. Parmacia, 5(1):32-34.
Staykov, V. and S. Ilieva, 1961. Essential Oil and Medicinal Plants, Sofia.
Stefanov, B., 1943. Phytogeographic elements in Bulgaria. 39 Coll. Bulgarian Academy of Science, 509 pp.
Stefanov, B. and B. Kitanov, 1962. Cultigenic Plants and Cultigenic Vegetation. Sofia.
Stoyanov, N., 1949. Our medicinal and aromatic plants. Sofia.
Stoyanov, N., 1964. Natural habitats and national resources of Leucojum aestrum L. in Bulgaria. Pharmacia, 14:5.
Stoyanov, N., 1966. Manual of medicinal plant collection. Sofia: Zemizdat, 625 pp.
Stoyanov, N., 1973. Our Medicinal Plants, Part II.
Stoyanov, N. and B. Avramova, 1957. Natural habitats and pharmacognostic investigation of the domestic Glycyrrhiza glabra L. Pharmacia, 4:17-22.
Stoyanov, N. and B. Avramova, 1958. Natural habitats of Atropa belladona L. Izv. Bot. Institute BAN (Proc. Inst. Botany Bulgarian Academy of Science), 6:391-402.
Stoyanov, N. and B. Kitanov, 1960. Useful wild plants in Bulgaria. Sofia: Bulgarian Academy of Science, 331 pp.
Stoyanov, N., B. Stefanov and B. Kitanov, 1966/1967. Flora of Bulgaria, vol I and vol II., 4th edition. Sofia: Nauka I izkustvo, 1324 pp.
Stoyanov, N. and P. Savchev, 1965. Natural habitats and national resources of Siler trilobum Grantz in Bulgaria. Pharmacia, 1.
Stoyanov, N., P. Savchev and J. Stefanov, 1965. Habitats and national resources of Vinca minor in Bulgaria. Pharmacia, 2.
Urumov, I., 1926. Materials on the Bulgarian folk medicine. BAN, XXII.
Valev, S., 1952. Medicinal plants in the Botevgrad region. Pharmacia, 2(4):14-18.
Velchev, V. (Ed), 1984. Red Book of Bulgaria. Vol. 1. Plants. Sofia: Bulgarian Academy of Science.
Velchev, V. and L. Evstatieva, 1983. Building a collection of medicinal plants in the botanical garden of the Institute of Botany. In: 90th Anniversary of academician D. Jordanov. Omurtag, pp. 137-142.
Velchev, V., L. Evstatieva and B. Tashkova, 1987. Introduction studies of some medicinal plants. In: Jubil. Sborn. Nat. Conf. Biol., 1986.