Heliamphora huberi

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

Identification

A rosette of erect pitchers, each formed from a single leaf grown shut into a funnel with a seam down the front. The pitcher widens towards the top and carries on the back rim a clearly free-standing nectar spoon — the small hooded organ that in Heliamphora has taken the place of the broad hood Sarracenia carries. That spoon is the thing to go by in this species, because it is neither as strongly reduced as in Heliamphora exappendiculata nor as broadly attached as in Heliamphora pulchella. The overall impression of the plant is intermediate: in size and pitcher shape it sits between the small species around Heliamphora minor and the sturdier ones around Heliamphora heterodoxa. Colour runs, as throughout the genus, from yellow-green in shaded plants to red in plants in full light. The inflorescence is a one-sided raceme on a long scape with nodding flowers whose tepals change colour as flowering proceeds.

Similar species

This is a species you identify not by one character but by the combination, and one that is surrounded on its own mountains by relatives. Heliamphora exappendiculata, of the same massif, lacks the free-standing spoon almost entirely and has a strikingly flat, spread pitcher mouth. Heliamphora pulchella, also of Chimantá, has a broadly attached spoon and a densely hairy pitcher interior. Heliamphora chimantensis of the same complex is considerably larger and forms extensive clonal mats. And then there are the hybrids: natural crosses of this species with exappendiculata and with pulchella have both been described, and those plants cannot be placed with certainty in the field. Anyone identifying on Chimantá does well to look at the whole population rather than a single plant.

The trap and how it works

A pitfall trap, with the division of labour that holds for the whole genus: the plant produces little or no digestive enzyme of its own and leaves breaking the prey down to bacteria and other micro-organisms in the pitcher fluid, then takes up the nitrogen and phosphorus compounds released. The nectar spoon on the back rim secretes nectar and stands directly above the opening, so an insect going for it is already over the trap. The upper zone of the inner wall bears downward-pointing hairs up which climbing back is impossible; below that the wall is smooth. A drainage slit in the wall regulates the water level and keeps a downpour on these exceptionally wet mountains from flushing the catch over the rim.

Habitat and ecology

The plateau of the table mountain (R4): bare sandstone with fissures, basins and hollows in which acid peat accumulates without anything that counts as soil in the ordinary sense. Within that landscape the plant grows mainly on the permanently wet ground with bog moss (W1), where water stands or seeps slowly through; on Akopán-tepui it forms extensive continuous stands there. The substrate is extremely poor in nitrogen and phosphorus and is continuously leached by the unremitting rain. The climate is cool and all but permanently wet; the massif lies in cloud for much of the day, and the temperature varies more between day and night than between seasons.

Distribution and elevation

Endemic to Bolívar state, Venezuela. The literature records the species from several component tepuis of the Chimantá massif — among them Akopán, Amurí, Apacará, Chimantá and Toronó — and also from Angasima-tepui, which belongs to the adjoining Aprada group. Sites lie roughly between 1850 and 2200 m. Beyond that listing the public distribution data do not go: no distribution region at all is recorded for this species in the international databases, so the map stays empty here and only the literature account remains. For a recently described tepui species that is no exception. The genus as a whole is confined to the table mountains of the Guiana Shield, in Venezuela, western Guyana and the far north of Brazil.

Forms and variation

No varieties or subspecies have been described. Plants do differ noticeably from tepui to tepui in size and pitcher shape, and on top of that there is the ordinary colour variation between green in shade and red in light; neither has been fixed with a name. What makes this species unusual is that its variation is itself a matter of debate: the structure intermediate between the minor and heterodoxa groups led its describers to consider a hybrid origin. Beyond that there is crossing in the wild today: natural hybrids with Heliamphora exappendiculata and with Heliamphora pulchella are known from the massif and show that species boundaries here are permeable.

Where and when to see it

The Chimantá massif can be reached only by helicopter or on a multi-day trek with a guide, and lies in protected territory. Search the wet, open parts of the plateau, where the species locally covers large areas, and not the rock faces — those are more likely to hold exappendiculata. Look first at the nectar spoon from the side: if it stands free on a stalk you are on the right track; if it is embedded in the pitcher apex it is another species. Then look at the pitcher interior, since dense hairs point to pulchella or to a cross with it. Nothing about the flowering period is 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 is known: the species occurs on several plateaus of the Chimantá massif and on Angasima-tepui, which by the standards of this genus makes it not especially rare; on some mountains it even forms extensive stands. The region is remote and cannot be entered without a permit, and there is no agricultural or mining pressure of consequence. At the same time the total range remains small, and the record of observations is so thin that not even a distribution region is listed for this species in the international databases. Collection for trade is the risk usually named for the genus, but material in cultivation comes almost entirely from seed and tissue culture. The absence of a formal assessment here means a gap in knowledge, not an established decline.

Scientific name

Heliamphora huberi | Fleischmann, Wistuba & Nerz, 2009

Described by Andreas Fleischmann, Andreas Wistuba and Joachim Nerz in 2009, in Willdenowia 39(2): 273–283. The species is endemic to the Chimantá massif in Venezuela, where it grows at 1850 to 2200 metres elevation across several tepuis, including Angasima, Apacará, Amurí and Acopán tepui and the border area of Torono and Chimantá tepui. The species name huberi likely honours the Austrian-Venezuelan botanist Otto Huber, who conducted extensive research on the flora of the Guayana Highlands; full certainty about this dedication could not be established.

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