Drosera elongata — Vorstman's Guide to the Carnivorous Plants

Identification

A sundew with an elongated, ascending stem along which narrow glandular trapping leaves are scattered, as in the related D. madagascariensis and D. affinis. Reliable measurements from a flora were not available for this text; the measurement fields are left empty.

Similar species

Drosera madagascariensis and D. affinis share the same habit; the distinction rests on details of leaf and flower and is difficult in the field. The rosette species of the region, such as D. burkeana and D. bequaertii, form no long stem.

The trap and how it works

An active flypaper trap. The leaves scattered along the stem catch small insects at different heights in the vegetation; after contact the tentacles bend towards the prey and the glands secrete digestive enzymes.

Habitat and ecology

Wet, open places on the plateaux: waterlogged grassland, dambos and marsh margins in savanna and open woodland (W4, W7, B6). Specific habitat data are scarce.

Distribution and elevation

Central Africa: known for certain from Angola; records from Zambia and southern DR Congo, as in this guide's working list, are plausible but not confirmed in the sources consulted. Altitudinal limits were not found.

Recorded (one-degree cells)

Distribution based solely on records at GBIF (Global Biodiversity Information Facility), not on TDWG regions — those are often far larger than the actual range. The light halo is the area around a record, the dark core the record itself. The darker cells are 4 one-degree squares — roughly a hundred and ten kilometres — in which the species has been recorded, from all GBIF records. This is coarser than for most species because hardly any record of this plant carries an accurate coordinate: the locality of poached species is obscured at source. At this scale that obscuring disappears into the noise. The cells show where it has been seen, not where it occurs: an empty square means nothing.

Forms and variation

No varieties are recognised. The species is known from few collections, and its delimitation from D. madagascariensis and D. affinis deserves new study.

Where and when to see it

Field records are rare and therefore valuable. Document stem, leaf and flower with photographs and have the identification checked by a specialist.

Conservation status

Assessed on the IUCN Red List as Data Deficient; not in CITES. That does not mean the species is safe, but that data on range and numbers are lacking.

Scientific name

Drosera elongata | Exell & Laundon, 1955

Described by Exell & J.R. Laundon in 1955, in Boletim da Sociedade Broteriana, series 2, volume 29, p. 42. Type material collected on 27 April 1937 by A.W. Exell & F.A. Mendonça, in Lunda Sul, Angola, locality "Tenga", near Luma-Cassai (holotype at BM). "Tenga", near Luma-Cassai, Lunda Sul province, Angola — an African species, unlike most other species in this golf. The species also occurs in Burundi, Congo, DR Congo, Tanzania and Zambia. From the Latin elongatus ("elongated") — probably referring to the elongated, scrambling stems (up to 90 cm), though this is not literally confirmed in a source.

World Checklist of Vascular Plants (WCVP), via Plants of the World Online (POWO), Royal Botanic Gardens, Kew.