Heliamphora parva — 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, each formed from a single leaf grown shut into a funnel with a seam down the front. The pitchers reach about 35 cm and have a low to mid-height waist, above which a drainage pore in the wall lets surplus rainwater run off. Colour is usually yellow to yellow-green; in plants in full light the upper part flushes red and fine red veins show on the inside. Characteristic is the often dense covering of short hairs on the outside of the pitcher. On the back rim stands the nectar spoon, here conspicuously large and red, and held upright rather than overhanging. The plant makes creeping stems up to some 70 cm that scramble over the rock, so that after years a single individual occupies a whole patch. At up to 80 mm the flowers are the largest in the genus.

Similar species

The obvious source of confusion is Heliamphora neblinae, which grows on the same mountains: its pitchers are 35 to 45 and sometimes 50 to 60 cm, roughly double, and carry a smooth, vivid red stripe down the back of the interior. Heliamphora parva stays smaller, is yellower, and is hairy on the outside where H. neblinae is much less so. The same massif also holds Heliamphora hispida, likewise hairy but bearing long, stiff hairs inside the pitcher rather than the short down on the outside. Find a medium-sized yellow pitcher with a large upright red spoon on the Neblina massif and you are with H. parva; if the pitcher runs up past the knee, it is H. neblinae. Confusion with Sarracenia is ruled out geographically.

The trap and how it works

A pitfall trap of the simple, open kind that marks the genus. There is no lid covering the mouth, only the nectar spoon on the back rim; a nectar-like substance is secreted there, drawing insects to exactly the wrong place. The upper zone of the inner wall carries downward-pointing hairs, so an insect that slips in cannot walk back up. The drainage pore halfway up the wall keeps the fluid level constant even in a climate where it rains almost daily: the pitcher never overflows. Digestion in this genus is left largely to bacteria in that fluid, after which the plant takes up the released nutrients. Old, dead pitchers remain standing and hold water; on these mountains that carries the plant through dry spells and even through fire, after which it resprouts from the stem.

Habitat and ecology

The summit country of the Neblina massif: open uplands of bare sandstone with wet meadows and hollows in which acid peat collects (R4, W6). The species stands in open upland meadows and in clearings among Bonnetia scrub, the small tree that forms the wood margins on many table mountains (B5). The largest populations lie in the north-west of the massif, at the lower end of the altitudinal range, around 1750 to 1850 m. The substrate is extremely poor in nitrogen and phosphorus and is leached by the near-permanent rain; the climate is cool and cloud sits on the plateau much of the day. A trap that turns insects into nitrogen is not incidental here but the condition of standing at all. Even so the plateau dries out periodically, and it is precisely to that that this species' water-holding build is tuned.

Distribution and elevation

Endemic to the Neblina massif, the border massif between Amazonas state in Venezuela and Amazonas state in Brazil, and found nowhere else. Known sites lie between about 1750 and 2200 m, concentrated on the southern part of Cerro de la Neblina. The genus as a whole is confined to the table mountains of the Guiana Shield — Venezuela, western Guyana and the far north of Brazil — and more than half its species stand on a single mountain. That is no accident: for a bog plant, plateaus separated by hundreds of metres of sheer wall and by lowland savannah are as unreachable from one another as islands at sea. The Neblina massif is the highest and remotest of those islands.

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

The species is itself the product of a split. Maguire described these plants in 1978 as Heliamphora neblinae var. parva, alongside a var. viridis; in 1984 the whole was placed as a form under Heliamphora tatei, and only in 2011, after new fieldwork, did parva receive species rank. The older names are therefore still widely met in the literature. Within the species there is clear wild variation in hairiness: besides normally hairy plants there are populations with a strikingly dense coat on the outside of the pitcher, without a taxonomic name of their own. Several species of the genus grow intermingled on the Neblina massif and natural hybrids and hybrid swarms have been described there, which makes identifying individual plants harder than on a mountain with a single species.

Where and when to see it

The Neblina massif lies within a national park and in a border zone, is reachable only by helicopter or on an expedition of weeks, and is among the least-visited places in South America; in practice every visit is made with a permit and with guides. Once on top, search not in the woodland but on the open wet flats and along the margins of the scrub. Read height and texture together: a pitcher up to knee height with a yellow, slightly woolly outside and a large red spoon held upright is this species. Watch the light rather than the season — colour says more about how exposed the spot is than about the time of year. 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 is certain is that the distribution is confined to a single massif, which makes any species vulnerable by definition to whatever befalls it. Against that, the area is protected, its position and inaccessibility mean it is barely entered, and the populations on the north-western part are large. The absence of a formal assessment owes mostly to the youth of the name and to how little of the area has been worked: there is too little fieldwork to establish population trends. The missing category therefore marks a gap in the record rather than a known decline.

Scientific name

Heliamphora parva | (Maguire) McPherson, Fleischmann, Wistuba & Nerz, 2011

Described by Stewart McPherson, Andreas Fleischmann, Andreas Wistuba and Joachim Nerz in 2011, in “Sarraceniaceae of South America” (Redfern Natural History Productions, Poole). The type area lies on the Neblina massif in Venezuela, at elevations of 1750 to 2200 metres. The species name parva is Latin for "small" and refers to this species' modest size compared to other Heliamphora species.

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