Drosera dielsiana — Vorstman's Guide to the Carnivorous Plants

Drosera dielsiana — the trap in close-up — **The trap in close-up** · Photo: incidencematrix — CC BY 2.0 · Wikimedia Commons

Drosera dielsiana — the flower — **The flower** · Photo: Michal Rubeš — CC BY 3.0 cz · Wikimedia Commons

Identification

A small, flat rosette of spatulate leaves with a short petiole passing into the blade and red tentacles. The scape rises from the centre of the rosette and carries a few pink flowers. Published measurements from a flora were not available for this text; the measurement fields are left empty.

Similar species

Drosera collinsiae and D. natalensis are very similar and are separated on details of leaf, stipules and hairiness; in the field that is hard without a hand lens. Drosera burkeana has shorter, broader, rounder blades, and D. madagascariensis forms a stem with scattered leaves.

The trap and how it works

An active flypaper trap: sticky droplets on stalked glands hold small insects, after which the tentacles bend towards the prey and the glands secrete digestive enzymes.

Habitat and ecology

Wet, open places in grassland and savanna: seeps, marsh margins and seasonally wet hollows, often on acid, nutrient-poor soil (W4, W7, B6). The plant grows and flowers in the wet summer.

Distribution and elevation

Southern Africa: eastern South Africa and neighbouring countries, north into Mozambique and Zimbabwe. Precise 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 16 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 belongs to a group of small rosetted sundews of the summer-rainfall region whose mutual boundaries are not always sharp.

Where and when to see it

Search in the wet summer months in marshy grassland and along seeps on mountain slopes. The rosettes are small; look in open, wet patches among the grass.

Conservation status

Assessed on the IUCN Red List as Least Concern; not in CITES. The range is large. Locally wet grasslands are lost to forestry, agriculture and drainage.

Scientific name

Drosera dielsiana | Exell & Laundon, 1956

Described by Arthur Wallis Exell & Jack Rodney Laundon in 1956, in Boletim da Sociedade Broteriana, series 2, volume 30, p. 214. The precise type locality could not be established. The species occurs in South Africa (KwaZulu-Natal, Free State, northern provinces), Eswatini, Mozambique, Malawi and Zimbabwe. Named in honour of Ludwig Diels, author of the influential 1906 monograph on the Droseraceae.

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