Lubomír ADAMEC, Institute of Botany of the Academy of Sciences of the Czech Republic, Section of Plant Ecology, Dukelská 145, CZ-379 82 Třeboň, Czech Republic


(according to the prepared Red Data Book of Endangered Plant Species of the Czech Republic, Ministry of Environ. CR; it will appear in 1998)

Aldrovanda vesiculosa - A1 - extinct (since 1995, Polish plants have been introduced to S. Bohemia)

Drosera anglica - C1 - critically endangered

Drosera intermedia - C1 - critically endangered

Drosera rotundifolia - C3 - endangered

Pinguicula bohemica - C1 - critically endangered

Pinguicula vulgaris - C2 - strongly endangered

Utricularia australis - C3 - endangered

Utricularia bremii - A2 - probably extinct (unknown occurrence)

Utricularia intermedia - C1 - critically endangered

Utricularia minor - C2 - strongly endangered

Utricularia ochroleuca - C1 - critically endangered

Utricularia vulgaris - C1 - critically endangered.


Aldrovanda vesiculosa

 This species occurred also in the Czech Republic: in 1952, it was found close to the Czech-Polish border near the town of Karviná. Later, this site was destroyed by mining coal and the plants disappeared. There is a historical record from the surroundings of the town of Litvínov in N. Bohemia (doubtful?). Thus, the recent status is extinct.  In 1993, a mass stock culture of A. vesiculosa collected from E. Poland was based in the Institute of Botany at Třeboň, CR. In 1994-95, experimental selection of potential suitable sites was performed in S. and N. Bohemia. In 1995, on behalf a NGO Biodiversity project, A. vesiculosa was introduced to several shallow dystrophic wetlands in Třeboň Biosphere Reserve and Protected Landscape Area in Třeboň region, S. Bohemia, CR. At the end of the 1996 season, the total introduced population reached ca. 6,000 shoot apices, while in 1997 ca. 12,500 ones at 3 sites. The plants grow in dystrophic pools on the margin of hypereutrophic fishponds. Water level over summer has been found as the crucial factor for vigorous growth of Aldrovanda. The minimum water level should be at least 5-8 cm of free water. In 1996-97, the pools started to be impacted by eutrophication. In the next years, some management will have to be done to remove redundant plant litter and dense emergent vegetation.

 Thus, all these introduced populations are endangered by very intensive fishpond management of the adjacent fishponds by fishpond company and by excessive decline in water level in hot and dry summer seasons. Yet, as an allochtonous plant population, Aldrovanda in the CR is not now under any type of state conservation! These sites are not under any type of local nature protection, either. Keeping of these introduced populations will only be dependent on habitat protection. A possible influence of collection of the plants by botanists or CP growers will be negligible.


Recent European distribution of Aldrovanda vesiculosa

Poland: out of the 78 historical sites, it has been verified recently (1993-97) that it still occurs on 9 sites (3: E. Poland; 5: NE. Poland; 1: W. Poland). The size of individual populations are between ca. 10 to 50,000 apices. At least 6 smallest populations are endangered by forthcoming lake succession. In 1996, Dr. Ryszard Kaminski (Wroclaw University) introduced the plants to 30 various potential suitable sites throughout Poland.

Status: critically endangered species.

Ukraine: it occurs in Lake Svit'yazke near Shack in W. Ukraine, at Domontovo island in the N. part of Kiev reservoir on the Dnieper river. In 1996-97, other two populations were found on the W. shore of Kiev reservoir and one population in Kiev, in the floodplain of the Dnieper river. In 1995, a population was found in the Ukrainean part of the Danube delta. In the Ukraine, the occurrence of Aldrovanda could be more abundant in the south, at estuaries of big rivers, and in the whole N. part of the country.

Status: critically endangered species.

Russia: critically endangered species. The only known recent site is that in common reed-dominated wetland on the SE. shore of Lake Ladoga near the estuary of the Sviri river. Probably, this northernmost population is the most abundant throughout the world. Growth of Aldrovanda was confirmed in 1997. It is highly probable, that it also occurs in several sites in Central and South Russia (e.g. delta of the Volha river).

Hungary: critically endangered species. The only last site is remaining, Baláta-tó (lake) near Somody in SW Hungary. After recent information from the 90s, the size of the population is of the order of magnitude of thousands of plants and the population seems to be stable.

Romania: critically endangered species. In the recent decade, Aldrovanda was found at some sites in the Danube delta region but accurate sites are not known. It could also occur at a few sites in Central Romania (e.g. near Brasov) but no recent information is available.

Switzerland: critically endangered species but there is no native record. In 1908, the plants from Lake Constance were successfully introduced to a peaty lake in the Zurich Canton and have been growing there up to now (population size: ca. a few thousands). In 1993, a proximate site near Kloten was described (a few thousands of plants). It probably arose as a result of turion transfer by water birds from the former site.

France: extinct. The species died out before 1969.

Germany: extinct. The species died out at the last site in Lake Heege near Sperenberg, 45 km S of Berlin, at the end of the 80s.

Italy: extinct. It died out at the last site in Lake Sibolla near Lucca in about 1985.

Slovakia: extinct. At the last site at Zelené jazero (lake) near Vojka in SE Slovakia, the species vanished in 1985. In summer 1997, it was introduced unsuccessfully to a fishpond near Malacky in the Záhorie Protected Landscape Area in W. Slovakia

 Aldrovanda might still occur in Belarus, Lithuania, Yugoslavia (Serbia), and Greece but the distribution has not been verified for long time.

 Generally, the rapid decline of Aldrovanda in all European countries has been caused mainly by water eutrophication, drainage, and filling in of water bodies. Other reasons may be more general land-use changes, particularly intensive agriculture, water level fluctuations, and wetland afforestation. Among others, high amounts of N in acid precipitates might accelerate eutrophication and, hence, native succession of shallow wetlands.

 To efficiently protect the European populations of Aldrovanda, all existing sites should be avoided of human impacts, the plants kept in (outdoor) stock cultures, and (re)introductions to suitable sites performed.


All the following comments refer to only Czech Republic:

Drosera anglica: Accurate recent distribution in the CR is not known. However, there are recent records from different parts of the country. It is possible to assume that the number of all sites does not exceed 20; the most abundant populations in the Czech Bohemian Forest (Šumava Mts., SW Bohemia) could have thousands of plants. In the Třeboň region (S. Bohemia), there are 5 small recent sites (ca. 20-250 plants).

Threats and conservation: Especially all lowland sites are endangered by peat bog eutrophication, water level fluctuations, drying out, filling in and overgrowing by tall dense vegetation or trees. The most sites are located in nature reserves but the eutrophication impact from adjacent hypertrophic fishponds (owned usually by fisheries companies) continues.

 This species is cultivated in the Institute of Botany, Section of Plant Ecology at Třeboň, in a conservation-based culture since 1993. Repatriation of plants to the Šumava National Park is being prepared.


Drosera intermedia: Accurate recent distribution is well-known in the CR. Natively, the species occurs in only the Třeboň region, S. Bohemia, in 5 sites. The population size ranges within ca. 20 - ca. [10,000] plants. Two out of these 5 sites are under local protection, the others not. At the end of the 80s, the plants from S. bohemia were introduced to a peat bog near Doksy in the Česká Lípa District. In 1997, the size of this introduced population was ca. 200 plants.

Threats and conservation: the same as in D. anglica. One site is under management of the Administration of the Třeboň Protected Landscape Area as a result of which an invasive grass Molinia coerulea is mown and the biomass removed. At 3 sites, the populations are partly damaged by high water level over summer but the plants seem to be relatively well-adapted to this factor.

The species is kept in a small conservation-based culture in the Institute of Botany at Třeboň.


Drosera rotundifolia: Recent distribution is not known in the CR. However, in some regions, it is rather common, with big populations exceeding even ca. 100,000-1000,000 plants while other populations have only dozens of plants. Totally, the number of all Czech sites may be between 500-1000. As many peat bogs and fens have been damaged or deteriorated in the recent decade (eutrophication, drying out, filling in, overgrowing by tall vegetation or afforestation, mining peat or fen) the number of sites is gradually decreasing. However, in some regions where it is still abundant new sites form permanently. In some regions with big populations (e.g. S. Bohemia), the plants were collected for medicinal use (droseran as antisclerotic agent) in the past but this practice is almost over.

 Conservation of this species should be based on protection of existing sites, especially on strict protection of isolated sites. A good deal of sites are in nature reserves or protected areas.


Pinguicula bohemica: Czech endemitic species. Former spread was at ca. 10 sites in N. and C. Bohemia. Recently, the species only occurs at 3 lowland sites in N. Bohemia in the Česká Lípa District. The sites form a group, with the distance of 1 km from each other. In 1997, the total size of the native populations was ca. 400 plants.

Threats and conservation: As the species is strictly confined to only a cation-rich, neutral or slightly alkaline peat or fen substrate, the chance to successfully colonize new site is practically zero. The species vanished from former sites due to eutrophication and overgrowing and any re-patriation is not reasonable. The species is very easily hybridized with more common Pinguicula vulgaris which rarely occurs at some extinct sites of P. bohemica.

 The last three sites are strongly endangered by decrease in ground water table in dry and hot seasons and overgrowing by tall invasive vegetation (Phragmites australis, Molinia coerulea, Carex sp., Juncus sp., Betula sp.). Dr. Miloslav Studnička, Head of the North Bohemian Botanic Garden in Liberec, CR, studied the ecology and conservation principles of P. bohemica in his PhD-thesis (1989) over the 80s. He prepared a sterile tissue culture of this species and using this and outdoor cultivation of this species in the Liberec BG, he has tried to repatriate ca. 300-400 plants to one site. The plants grow successfully (in 1997). Such a measure can easily be applied to large areas of the site (up to 0.1 ha totally with ca. 10,000 plants). Otherwise, a strict protection of the all existing sites is necessary. Nowadays, a National Nature Reserve Polomené Mountains is being prepared. It will cover 2 out of the 3 sites. Otherwise, the sites are not protected recently.

 The very small populations are also endangered by CP growers or botanists who sometimes collect some plants. About 2 years ago, a CP grower collected plenty of repatriated plants and offered them for sale. The recent protection of the sites depends fully on Dr. Studnička. A regular management of the sites will have to be done in a very near future.


Pinguicula vulgaris: the total number of populations is probably between 10-20. Highland populations in the Šumava National Park (SW. Bohemia) can have thousands of plants and are not endangered. In contrast, all lowland populations are critically endangered as the habitats are overgrown by tall vegetation and trees. Thus, the protection of all existing sites is more or less dependent on regular management and the need for such a management will be growing in the future. Similarly as in other Czech terrestrial and aquatic CP species, an effective protection would also require to cancel intensively agricultural land in the surroundings of the sites. The most sites are in nature reserves.

 The technique of artificial propagation of the species has been managed in the CR in the last 5 years. Thus, repatriation projects could be started.


Utricularia australis: very common species over the whole area of the CR, able to grow also in eutrophic fishponds in reed littoral zone. The total number or Czech sites may be between 1000-2000. The species is ecologically very plastic, easily spread by water birds and, thus, any conservation is unnecessary.


Utricularia bremii: not verified species for the last 30 years.


Utricularia intermedia: the species occurs in only the Třeboň region and only 7 sites were verified recently. The size of 5 populations is between ca. 10,000-1000,000 plants (apices). Other 2 sites are endangered by drying out and competition.

Threats and conservation: As all populations grow in shallow dystrophic wetlands connected to hypertrophic fishponds mineral nutrients leak from the fishponds and entry the sites. Thus, the eutrophication impact is serious though the size of most populations is nearly constant over the last 5 years. Summer fall in water level or even drying out represent the main unfavourable factor which can drastically reduce the populations for some years. However, as shown recently the populations have a great capacity to rapidly recover abundant populations after water regime is optimized. Functional seeds probably play the main role to keep the continuity of population after several years of drought. The species cannot grow on moist soil permanently.

 To keep the populations stable, the eutrophication of fishponds should be reduced. Four out of the 7 sites occur in nature reserves but this does not reduce the eutrophication impacts. It is possible to assume that some management of the sites will be desirable in the future.

 The technique of outdoor cultivation has been managed in the Institute of Botany at Třeboň and the species has been listed to the conservation-based cultures.


Utricularia minor: is more or less distributed in all regions of the CR. The total number of all sites may be between 60-100, with a denser occurrence in S. and N. Bohemia. In the Třeboň region, 13 sites have been verified recently. The size of these populations is between ca. 100-1000,000 plants (apices) but small populations of ca. 1000 plants are prevailing.

Threats and conservation: As most sites in the CR are very shallow and many of them are gradually subjected to eutrophication from the adjacent hypertrophic fishponds, many of them are more ore less endangered by filling in and overgrowing. Other sites seem to be very stable. This species is ecologically very plastic and probably has a great propagation capacity in favourable conditions. In the CR, the half or even more sites are without any protection. The protection should prevent from summer drying out of the sites and ensure a minimal eutrophication impact.


Utricularia ochroleuca: only 14 sites have been verified recently in the CR. Two sites are near the town of Františkovy Lázně in W. Bohemia, one site is in a pool in the Vltava river floodplain in SW Bohemia, and 11 sites are in the Třeboň region. Here, the size of populations ranges within ca. 20-100,000 plants (apices).

Threats and conservation: Only the minority of the sites is under local protection. For the other principles see U. intermedia and U. minor. The smallest populations are strongly endangered (filling in, overgrowing).

 The technique of outdoor cultivation has been managed in the Institute of Botany at Třeboň and the species has been listed to the conservation-based cultures.


Utricularia vulgaris: recent accurate distribution in the CR is unknown, however, some 10-20 sites may be assumed. The only distribution is in C. and NW. Bohemia and S. Moravia, in the warmest lowland regions in the CR.

Threats and conservation: A good deal of the sites are in nature reserves. The sites are endangered mainly by eutrophication of fishponds and pools. The main conservation measure is to reduce the eutrophication impact of fisheries and/or adjacent agricultural land.

 The technique of outdoor cultivation has been managed in the Institute of Botany at Třeboň and the species will be listed to the conservation-based cultures.


B) Propagation (restoration) projects have only been fully realized for Pinguicula bohemica, P. vulgaris, and Aldrovanda vesiculosa. In the latter species, the project was supported by a NGO GEF Biodiversity Foundation and was worked out in collaboration between the Czech Union for Nature Conservation at Třeboň and the Institute of Botany at Třeboň. The primary experimental project on Aldrovanda was supported by the Academy of Sciences of the CR (1994-95).

 Otherwise, the general role in conserving CPs belong to the Ministry of Environment of the CR, Section of Nature Protection, and to Agency of the Nature and Landscape Protection of the CR, which supports the conservation-based cultivations in the Institute of Botany at Třeboň including also CPs.

C) The recent legislation on CPs protection is based on the Law on Nature and Landscape Protection No. 114 from 1992. On the basis of this Law, particularly protected animal and plant species are stated. The list of these species in 3 categories (critically end., strongly end., and endangered species) is given by the Announcement No. 395 from 1992. According to this Announcement, the critically endangered species are: D. anglica, D. intermedia, P. bohemica, U. bremii, U. ochroleuca, U. vulgaris; strongly endangered: D. rotundifolia, P. vulgaris, U. intermedia.

Note that this concept differs greatly from that accepted recently for the Red Data Book of the Endangered Plants of the CR prepared (see above)!

 After the Law No. 114, the particularly protected plants must not be collected (both above- and underground parts) or otherwise damaged. Their biotope must not be damaged, too. Their seeds must not be collected, either. Foreign export of these species is forbidden. Collection or damage of these species is penalized. However, although this Law strictly protects the plants of these species from direct damage this Law is in practice very weak concerning the habitat protection. Very many fishponds in the CR are (national) nature reserves but in spite of this status, the fishponds are very intensively managed and hypertrophic, which reduces biodiversity in these nature reserves. In fact, there is a very weak respect to this Law from many economic organizations (e.g. pig farms, fisheries, etc.). Otherwise, the Czech legislation respects the CITES Convention.

Luckily, the effort of scientists and state conservationists to protect habitats and to restore them, when necessary, is going to be gradually stronger and stronger.

D) Trade in CPs: A few dozens of layman CP growers in the CR grow outdoors the most terrestrial Czech CPs. The plants mostly originate from wild plant populations.

 Some CP growers state in their advertisements the sale of seeds of all 3 Czech Drosera species and of P. vulgaris. The seeds originate partly from collection of seeds from wild plants but mostly from home outdoor collections. The market of domestic CPs is not extra organized and is realized by several individual CPs growers as hobbyists (i.e. retail). From traditional reasons, there is a very frequent transfer of plants or seeds between the CR and Slovakia. I suppose that the illegal aspect of the trade in Czech native CPs will diminish in time as the State Inspection will be more thorough in the future and the indigenous market has been almost saturated.