Drosera tentaculata — Vorstman's Guide to the Carnivorous Plants

Identification

A perennial rosette plant whose leaves stand out for long red tentacles along the margins of the blade, projecting well beyond it and giving the rosette a gossamer, spiky look. In sun the plant turns red. The scape carries several flowers. Exact measurements and a confirmed flower colour could not be checked from the original description; the size fields are left empty.

Similar species

The long marginal tentacles separate it from most other sundews in the same area, such as Drosera communis, Drosera latifolia and Drosera tomentosa. Drosera riparia also grows in the Chapada Diamantina, along riverbanks. In young or shaded plants the marginal tentacles are less conspicuous, and then comparison with the original description is needed.

The trap and how it works

An active flypaper trap, in which the long marginal tentacles extend the leaf's reach. As in other sundews with long marginal tentacles, they can bend a captured insect towards the centre of the blade, where the short, more crowded glands take over digestion. Prey consists of small flying and crawling insects.

Habitat and ecology

Campos rupestres on quartzite and sandstone: wet sandy ground, seepages along rock slabs and the wet edges of streams, in open, sunny vegetation (R1, W4, D2). The landscape has a long dry season during which the sites partly dry out.

Distribution and elevation

Endemic to Brazil, in the highlands of the Espinhaço range in the states of Minas Gerais and Bahia, including the Chapada Diamantina. A published altitudinal range has not been adopted.

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 6 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 2003 paper in which the species was described marked the start of a series of publications in which Rivadavia, and later Gonella and Fleischmann, thoroughly revised the Brazilian sundew flora; the number of recognised Brazilian species has risen sharply since.

Where and when to see it

In the wet season search seepages and stream edges in the national parks of the Chapada Diamantina or the Espinhaço of Minas Gerais. Look at the rosettes from the side in low light: the long marginal tentacles show best then.

Conservation status

Not assessed for the global IUCN Red List and not listed in CITES. The range covers two states and lies partly in protected areas. Threats to the campos rupestres are fire, invasive grasses, mining and tourism.

Scientific name

Drosera tentaculata | Rivadavia, 2003

Drosera tentaculata was described in 2003 by the Brazilian botanist Fernando Rivadavia, in the article "Four New Species of Sundews, Drosera (Droseraceae), from Brazil", published in Carnivorous Plant Newsletter, volume 32(3), p. 79–92. The holotype was collected on 31 July 2002 by F. Rivadavia and R. Gibson in Brazil, in the state of Minas Gerais, Diamantina municipality, at the locality "at the top of the Cachoeira dos Cristais, on the road to Biribiri" (in the Espinhaço mountain range). The holotype (SPF 157000) is held at the Herbário da Universidade de São Paulo (SPF). The name tentaculata derives from Latin tentaculum ("tentacle, feeler") and means "furnished with tentacles". The name refers to the conspicuously developed, unifacial marginal glandular hairs ("snap tentacles") that characterise this species.

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