Heliamphora neblinae — Vorstman's Guide to the Carnivorous Plants

No photograph of this species under a Creative Commons licence or in the public domain is in the guide yet.

Identification

Substantial, erect pitchers, each formed from a single leaf grown shut into a funnel with a seam down the front. They usually reach 35 to 45 cm, not seldom 50 to 60, making them the longest in the genus. Characteristic is a smooth, vivid red stripe running down the back of the interior, sharply set off against the rest of the leaf. The plants are slow: it takes years for a rosette to reach full size, and older individuals build a short stem up which the rosette works its way, so that with time the plant stands above its own dead leaves. On the back rim, as throughout the genus, stands the nectar spoon. Within its range the species is unusually variable in size and colour, which makes identifying single plants harder.

Similar species

Three species on the same massif raise the question of confusion. Heliamphora parva reaches at most 35 cm, is yellower and densely short-hairy on the outside. Heliamphora ceracea, of the Brazilian slopes, is 20 to 30 cm, narrower and tubular, with a waxy, bare inner wall bearing large irregular gland patches. Heliamphora hispida carries long stiff hairs inside the pitcher. Size alone is often decisive: if the pitcher runs up to knee height or beyond, only H. neblinae comes into question on this massif, and the red stripe on the back wall confirms it. Further afield Heliamphora tatei, of Cerro Duida and its surroundings, closely resembles it — the two were long treated as one species — but their ranges do not meet.

The trap and how it works

A pitfall trap of the open kind: no lid, only the nectar spoon on the back rim as the lure. The upper zone of the inner wall carries downward-pointing hairs, so an insect that slips in cannot walk back up. What sets this group apart within the genus is digestion. Most Heliamphora species leave breaking the prey down to bacteria in the pitcher fluid, but in the closely related Heliamphora tatei the plant has been shown to secrete proteolytic enzymes of its own and to form wax scales that assist capture as well. The large pitchers of H. neblinae hold a great deal of water, which carries the plant through drier spells on these slopes. The whole is thus a trap both larger and more self-sufficient than the average in this genus.

Habitat and ecology

The Neblina massif across its full range: from wet plateaus with bog moss and acid peat over bare sandstone (R4, W1) to open, wet upland meadows and boggy hollows lower down the slopes (W6). The altitudinal range runs from about 860 to 2200 m — the lowest site known for the entire genus. The soil is everywhere extremely poor in nitrogen and phosphorus and is leached by the near-permanent rain, the climate is cool and wet, and cloud lies on the mountains much of the day. That the species occupies that whole span partly explains its variability: plants on the high plateaus stand in different light, temperature and substrate from those on the low slopes, and they look different too.

Distribution and elevation

Endemic to the Neblina massif and the adjoining summits: Cerro de la Neblina, Cerro Aracamuni and Cerro Avispa, in Amazonas state in Venezuela and, on the southern side of the massif, in Amazonas state in Brazil. Across those three mountains the species is widespread, which by the standards of this genus makes it almost broadly distributed: more than half of all Heliamphora species stand on a single mountain. The genus as a whole is confined to the table mountains of the Guiana Shield — Venezuela, western Guyana and the far north of Brazil. Within that, the Neblina massif is the highest and remotest complex, and holds more species of the genus than most other mountains.

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 5 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

The nomenclatural history is untidy and not yet fully settled. Maguire described the species in 1978; in 1984 Steyermark reduced it to Heliamphora tatei var. neblinae, a treatment followed for years afterwards, including in the 1989 floral-biology work on H. tatei at Cerro de la Neblina. McPherson (2007) and the 2011 monograph restore it as a species in its own right, and POWO follows that; the GBIF backbone at present still holds to the variety. Both names are therefore in circulation. Wild variation within the species is considerable — size, colour and hairiness differ markedly by mountain and by altitude — without varieties having been distinguished for it. The plants known as H. tatei f. macdonaldae are likewise regarded by some authors as a species of their own. Natural hybrids and hybrid swarms with other species of the genus have been described on the massif.

Where and when to see it

The Neblina massif lies in protected land on both sides of the border, partly on indigenous territory, and is reachable only by helicopter or on an expedition of weeks; visits are made with a permit and with guides. Once up, you need not search long for this species: its size makes it one of the most conspicuous plants of the mountain on the wet, open ground. Watch the inside of the back wall — the smooth red stripe is the quickest character — and do not be misled by the strong variation: a small plant on this massif is more likely a young individual or another species than an aberrant H. neblinae. The flowering period of the species is not established in the literature.

Conservation status

The species has not been assessed for the IUCN Red List, and there is no CITES listing: Heliamphora appears in no appendix. What can be said is more favourable than for most species of the genus: it occurs on three mountains, is widespread across them and spans a wide altitudinal range, which makes it less vulnerable than a species of a single plateau. The area is besides protected on both sides of the border and is among the hardest-reached corners of South America. Collection for trade is the risk usually named for the genus; material in cultivation now comes almost entirely from seed and tissue culture. The absence of a formal assessment is bound up here with the unsettled naming — a species is hard to assess under two names — and with the small amount of fieldwork. It is a gap, not an established decline.

Scientific name

Heliamphora neblinae | Maguire, 1978

Described by Bassett Maguire in 1978, in “The Botany of the Guyana Highland Part–X”, Memoirs of the New York Botanical Garden 29: 36–61. The species is endemic to three mountains in Venezuela: Cerro de la Neblina, Cerro Aracamuni and Cerro Avispa. The species name neblinae refers to the type locality, Cerro de la Neblina ("mist mountain"), the highest peak of the Guiana Highlands.

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