Heliamphora collina — 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

A rosette of erect pitchers about 25 cm long in the wild, which over the years forms tidy, upright clumps. Each pitcher is a single leaf grown shut into a funnel with a seam down the front. The shape is notable in being less cylindrical than in its closest relatives: it tapers and bellies more distinctly along its length. The colour is pale yellow-green and usually stays that way, which follows from the shaded site. Halfway up the pitcher wall sits a drainage pore that regulates the fluid level. The diagnostic character sits on the back rim: the nectar spoon here does not form a chamber, whereas in the most closely related species it does — a small but reliable difference you can check with a hand lens. Measurements of the scape and floral parts are not established in accessible literature.

Similar species

The species closest to it is Heliamphora folliculata, from the same mountain group; there is a reason growers have nicknamed collina the little folliculata. The distinction lies in the nectar spoon: in folliculata it forms a clear chamber, in collina it does not. Collina also stays more compact and its pitcher is less cylindrical. On Ptari-tepui you may additionally meet the species alongside Heliamphora purpurascens, but that grows hundreds of metres higher on the summit plateau, at around 2400 to 2500 m, and flushes deep purple rather than staying pale yellow-green. Elevation is therefore a useful aid for those two. Confusion with Sarracenia is ruled out geographically.

The trap and how it works

A pitfall trap that leaves the breakdown of prey largely to bacteria: the plant produces few or no digestive enzymes of its own and takes up the released nitrogen and phosphorus. The nectar spoon on the back rim secretes nectar and brings insects to just above the opening. The upper part of the inner wall is lined with downward-pointing hairs, so that prey once inside cannot walk back up; below that the wall is smooth. The drainage pore halfway up keeps the fluid at a constant level, so that persistent rain does not flush the catch out of the pitcher. Characteristic of this species is that the trap often lies largely buried in leaf litter, with only the mouth left clear.

Habitat and ecology

Wet seepage sites in low, dense scrub and grassland on the foothills (W6), between about 1700 and 1825 m. The substrate is permanently soaked by water seeping through, and in the wettest spots acid peaty material with bog moss accumulates (W1). What makes this site distinctive is the dense, low vegetation around it: the plants are often largely buried under moss and leaf litter, so that only the pitcher mouth still protrudes above the layer. That explains the pale colour straight away, since little direct light falls on the pitchers. The climate is cool and wet, though less extreme than up on the plateaus. Here too the substrate is extremely poor in nitrogen and phosphorus, and the through-flowing water continually carries away what there is.

Distribution and elevation

The species is endemic to Venezuela, Bolívar state, and occurs on the foothills and lower hills of the Los Testigos chain — among others near Aparamán-tepui, Kamarkawarai-tepui, Murisipán-tepui and Tereke-yurén-tepui. It was initially held to be endemic to that chain alone, but in 2018 it was also found on the south-western slopes of Ptari-tepui. Known sites lie between about 1700 and 1825 m. Global checklists give Venezuela alone as this species' range. Precise sites are left out here. That a species which appeared to be endemic to a single massif turned up on a neighbouring mountain seven years after its description shows how incomplete the picture of this genus still is.

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 2 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 or subspecies have been described. The variation you see is limited and mostly a matter of site: plants sunk deeper into the litter are paler and stretch their pitchers further, plants at a more open edge stay stockier and colour a little more. How the plants of Ptari-tepui relate to those of the Los Testigos chain has not been worked out in detail; the 2018 find is recent and the populations have not been systematically compared. No natural hybrids are recorded for this species in accessible literature, not even with the related species of the same massif.

Where and when to see it

The foothills of Los Testigos and Ptari-tepui lie within Canaima National Park and are reachable only on a multi-day trek or by helicopter; visits are made with a permit and a guide. The search image here differs from that of the plateau species: do not expect to see whole rosettes standing clear. What you usually find is a pale pitcher mouth pushing up between moss and litter, and that calls for stooping low at seepage sites in dense, low scrub. Take a hand lens for the nectar spoon, since that is where the distinction from the related species hangs. Do not rake open the litter to see a plant better; the rosettes sit shallowly in it and the layer recovers slowly.

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 that the known distribution covers the foothills of several mountains in one chain plus a second massif, which is wider than for most of its relatives, which make do with a single plateau. The extension of the known range in 2018 suggests the species probably stands in more places than are currently recorded. Against that, foothills are less inaccessible than a table-mountain summit, and the entire habitat falls within a narrow altitudinal band of less than one hundred and fifty metres. The habitat lies within a national park and World Heritage site. Collection for trade counts as a risk for the genus, but cultivated material now comes almost entirely from seed and tissue culture. The absence of an assessment here is a gap in the record, not an established decline.

Scientific name

Heliamphora collina | Wistuba, Nerz, McPherson & Fleischmann, 2011

Described by Andreas Wistuba, Joachim Nerz, Stewart McPherson and Andreas Fleischmann in 2011, in “Sarraceniaceae of South America” (Redfern Natural History Productions, Poole). The type area lies on the Los Testigos and Ptari-tepui massifs in Venezuela, at elevations of 1700 to 1825 metres. The species name collina is Latin for "of the hills" and refers to the species' habitat on rolling slopes.

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