Endangered Drosera Ark
The Endangered Drosera Ark is a permanent ex-situ conservation collection of Drosera taxa that are critically endangered, extinct, near extinct or functionally extinct in the wild.
The purpose of the collection is to ensure the survival of the genetic diversity of the most imperilled Drosera taxa to stop extinction, maintain a viable breeding population and keep alive the hope of future reintroduction back into the wild.
Why are Drosera Endangered?
Drosera (also known as sundews) occur across the world from the summits of mountains to wetlands across all continents except Antarctica. They occur from the high latitudes of the north to the southern tip of South America, although the genus is notably absent from arid areas and many remote oceanic islands. Around 200 species of Drosera are currently recognised.
Drosera catch (mainly insect) prey by way of droplets of sticky mucilage which are borne on glandular tentacles that cover the leaves of most species. In some Drosera, the leaves and the tentacles move and wrap around victims, to smothering prey, release copious digestive fluid and aid absorption of resulting nutrients.
Many Drosera species are widely distributed and not at any risk of extinction at the current time. Others have highly localised natural ranges and are endemic to very specific niche habitats. In case of a few taxa, the entire wild population may be a few thousand individuals (e.g. D. regia).
Many Drosera species across the world have suffered from habitat destruction and displacement, and several species are in decline.
In comparison to other genera of carnivorous plants, poaching is generally less of a threat to most Drosera species. Many factors explain this: (1) although a few Drosera taxa are grown very widely, most Drosera species are cultivated by a relatively small number of horticulturists, (2)
many Drosera species can be easily propagated and more than satisfies global demand, (3) many Drosera species are short lived (or annual), (4) many Drosera (especially annual species) transplant poorly (as living specimens) from the wild into cultivation and (5) many Drosera species (especially annual ones) have a relatively low value in cultivation.
There are exceptions. Many species of long-lived tuberous Drosera of Australia are highly valued among horticulturists, and several populations have been targeted by poachers, with extensive numbers dug up illegally and sold.
The Endangered Drosera Ark focuses on the conservation of the following Drosera species which, for varying reasons, are seriously threatened in the wild.
The Ark of Life team are in the process of adding several additional Drosera species to the Endangered Drosera Ark.
Drosera cistiflora occurs across wetlands in the Western Cape of South Africa, from the hinterlands of Cape Town and the Cape Range, through the sandstone plateaus between Ceres and Nieuwoudtville, and as far east as Port Elizabeth.
This species is one of the most variable of all Drosera species, occurring in a spectrum of variation in the wild. Each population varies in overall plant size, leaf colour, leaf shape, leaf length, leaf width, leaf density, tendency to form a stem, flower size, and particularly, flower colour. See the six images below that showcase some of the variability of this beautiful plant in the wild.
Although Drosera cistiflora (as a species) is not at risk of extinction, many of the distinctive forms are extremely rare in the wild, and populations across the species’ range are rapidly diminishing as habitat clearance for agriculture, wetland drainage and development take place. The loss of each population erodes the important diversity of Drosera cistiflora.
The Endangered Drosera Ark permanently conserves as many of the distinctive variants of this species as possible, especially those representing wild populations that are extinct or seriously threatened.
The remarkable natural diversity of Drosera cistiflora. Many populations of this species are vanishing, and with them, the astoundingly beautiful variation of this species.
Drosera coccipetala is named for its bright red flower colouration (which is unusual in the genus Drosera). The specific epithet is derived from the Latin coccinus (scarlet) and petalum (petal). This species is endemic to South Africa where it grows on the south coast near the town of Caledon.
It is known from only a handful of sites characterised by seasonally moist clay loam in low fynbos ericoid shrubland. Most of these sites occur within agricultural areas and are very vulnerable. Several have disappeared in recent years due to drainage of land for agricultural use.
Due to this species’ very small range, its long-term security in the wild is dependent on the good will and land management practices of local farmers and needs to be monitored closely.
Drosera regia is named from the Latin regius (royal) and is known as the king sundew for it produces among the largest and most spectacular leaves in the genus. Each leaf is sword shaped, up to 40 cm long, and highly mobile (both in terms to tentacles and the lamina), responding to trapped prey by slowly bending, twisting and even coiling.
This species can be considered a living fossil; it is the basalmost branching lineage of extant Drosera and it has many “archaic” characteristics not seen in most other members of the genus, especially not in combination. For example, creeping, horizontal rhizome, leaves without petioles and stipules, no gland dimorphism, and pollen with germ-pores covered by operculae. The latter link this species to the sister genera of Drosera, namely Dionaea and Aldrovanda.
This beautiful species has a highly localised range. It is endemic to the Bainskloof Range in South Africa. It is known from only a handful of small populations at montane elevations. At least one of these populations has been extirpated during recent years. Each of the surviving sites consists of a few hundred plants or less (some of the smaller sites comprise just a dozen or so specimens). The total wild population is thought to be a few thousand plants at most. At least one of the larger surviving stands appears to be in serious decline (Stewart Mcpherson, pers. observ. during regular visits between 2006 and 2017).
Drosera regia grows in permanently wet peaty soils of slopes drained with cool, seeping water. The habitat of D. regia is prone to occasional wildfires, and plants vigorously re-sprout from rhizomes and roots following fires, when competing surrounding vegetation has been burnt away. Without regular wildfires, its habitats are quickly overgrown, especially by vigorous rushes.
The survival of this species in the wild depends upon the maintenance of its fire-dependent habitat. It is easy to imagine this species being displaced relatively quickly if natural fire activity is suppressed for extended periods of time. Locals report the Bainskloof Range is becoming increasingly dry and historic evidence (e.g. photographs) seem to support this claim. A hotter, drier climate in South Africa could also seriously jeopardise the survival of D. regia by reducing the flow of seepage water upon which this species depends.
Drosera solaris is an unusual sundew species from South America that is distinctive for forming upright towers of dead foliage. Unlike related species (e.g. D. roraimae), it produces flowers that are positioned amongst its leaves and when pollinated, it forms splash cups that distribute its seed via rain drops.
This species has only ever been observed on one occasion, when it was discovered by Stewart McPherson, Andreas Wistuba and Barbara Kistler on Maringma Tepui in a clearing within Bonnetia forest.
The habitat of Drosera solaris is atypical for tepui summit Drosera, not being near a swamp, river or seepage, but simply a mossy clearing within forest. Many Drosera, like D. roraimae, grow etiolated amongst Bonnetia trees, generally poorly and without flowering. However, the entire population of Drosera solaris was observed growing very healthily in a peaty substrate of leaf litter and organic matter generally in light shade.
The entire population of the Drosera solaris occurred within an area of ca. 50 m2. Though the mountain has been visited by a number of research groups—mainly zoological—since that time, D. solaris has not ever been observed again.
On the basis of current field observations, Drosera solaris appears limited to its tiny type locality, which makes it, by far, the most localised of all carnivorous plants in terms of its geographic range. A single catastrophic event (e.g. a fire) could wipe out the entire known population.
As such, Drosera solaris is included in the Endangered Drosera Collection, although, the Ark of Life team acknowledge if further populations of this species are discovered, its imperilled status may need to be revised.
SUPPORT THE ENDANGERED DROSERA ARK
Donate funding to help Ark of Life expand this collection.
Donate cuttings or divisions of plants in your collection.
The Endangered Drosera Ark comprises the following genetically distinct strains. Each strain is labelled with a unique “asset number”. The asset number consists of 4 letters and numerals. Each asset number is unique to a specific genetic strain. If that strain is lost, the asset number is abandoned.
|CIST4||white and pink flower|
|CIST6||white flower with black centre|
|CIST7||red flower with black centre|
|CIST15||tall stem form|
|CIST16||short stem form|
|COCC1A22||Near Caledon - strain 1|
|COCC2||Near Caledon - strain 2|
|COCC3||Near Caledon - strain 3|
|REGI4A30||white flowered form|
|SOLA1A34||Maringma Tepui type locality|