Drosera rubrifolia — Vorstman's Guide to the Carnivorous Plants

Identification

A small, flat-lying rosette with a very vivid dark red colour in leaf and tentacles. The leaf shape resembles that of D. slackii: a flat petiole passing into a widened trapping blade. The young leaves, however, lack the short fleshy projections on the underside that characterise D. slackii. Reliable measurements and a flower colour from the original description were not available for this text; the measurement fields are left empty.

Similar species

Drosera slackii is larger, less deeply red and has fleshy projections on the underside of the unrolling leaves. Drosera aliciae has narrower spatulate leaves with a hairy underside and distinct stipules.

The trap and how it works

An active flypaper trap: stalked glands with sticky droplets hold small insects, after which tentacles bend towards the prey and digestive enzymes are secreted. The deep red colouring by anthocyanin is a response to strong light.

Habitat and ecology

By analogy with the related D. slackii, probably permanently wet seeps in mountain fynbos, on nutrient-poor peaty sand over sandstone (R1, W4, B5). Precise habitat data are not given here.

Distribution and elevation

Endemic to the south-western Cape of South Africa, known from the Ceres area. The species is known from very few sites; this guide gives no localities. 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 square is the only one-degree cell — 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. It shows where the species has been seen, not where it occurs: an empty square means nothing.

Forms and variation

No varieties. The species belongs to the series of Cape rosetted sundews that Debbert described around the turn of the century. Kew accepts D. rubrifolia as a species. In cultivation it is raised from seed, which will hopefully reduce pressure on wild populations.

Where and when to see it

This species is not a suitable target for a field visit. Anyone who comes across it in the mountains around Ceres should leave it be and not share the site publicly.

Conservation status

Not assessed for the global IUCN Red List and not listed in CITES. Its very small range makes the species vulnerable to any change at its seeps, to invasive alien plants, to a disturbed fire regime and to illegal collecting.

Scientific name

Drosera rubrifolia | Debbert, 2002

Drosera rubrifolia was described in 2002 by Peter Debbert, published in Linzer Biologische Beiträge, volume 34, page 798. The holotype (collection no. Debbert 132) originates from South Africa, Cape Province, from the mountains near Ceres and Tulbagh, in sites that are very wet year-round. The collection date could not be established with certainty. The epithet rubrifolia is composed of the Latin ruber ("red") and folium ("leaf"), and thus means "red-leaved" — a descriptive reference to the colour of the plant's leaves.

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