Nepenthes monticola — 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 strong climber with stems usually up to four metres long, angular in section, up to 6 mm thick and reddish in colour. Rosette leaves are 7 to 12 cm long, leaves of the climbing stem up to 15 cm, with a narrowed base running down the stem. Lower pitchers are narrowly ovate, narrowing to a distinct waist and then cylindrical, to 12 cm tall and 3.5 cm wide, with a mouth tilted at about 40 degrees and a terete to slightly flattened peristome of 2 to 5 mm with fine striations. Upper pitchers are narrowly ovate below and cylindrical to funnel-shaped above, to 18 cm tall and 5 cm wide, with a flattened front. The plant is nearly hairless, with only scattered very short black hairs.

Similar species

The only serious source of confusion is Nepenthes lamii, in which the species was placed until 2011. Nepenthes lamii in the strict sense is a compact, largely upright plant with red stems and bulbous pitchers, growing above the treeline at over 3200 m. Nepenthes monticola is a true climber with angular stems and waisted lower pitchers, and grows lower, between 1400 and 2620 m, in mossy montane forest. Altitude and habit are therefore the first clue in the field. From Nepenthes maxima, which occurs in the same mountains, it differs in its much smaller pitchers and the absence of appendages under the lid.

The trap and how it works

A pitfall trap that invests heavily in attraction. Nectar glands under the lid are very dense, 1400 to 2000 per square centimetre, a feature shared with Nepenthes lamii. Insects drawn to the nectar that walk over the peristome slip once the ridges are wet and end up in the digestive fluid. Lower pitchers stand in rosettes close to the ground and in the moss and mainly catch walking animals; upper pitchers hang from long tendrils in the mossy vegetation and also catch flying insects. In the cool montane forest insects are less abundant, which makes a strong lure per pitcher worthwhile.

Habitat and ecology

Terrestrial, occasionally epiphytic, in bright conditions among stunted, mossy upper montane vegetation, at 1400 to 2620 m (B1, B5). The species favours light places: open parts of the cloud forest, forest edges, scrub and vegetation recovering after disturbance. The climate is cool and nearly always damp, with much cloud and rain. The soil is nutrient-poor, often peaty or covered by a thick layer of moss, so that prey forms an important supplement to what the roots take up.

Distribution and elevation

Endemic to the west-central uplands of the Indonesian province of Papua, on New Guinea, where it occurs on a number of mountains. Our own species list gives 'New Guinea', which is correct, but all known sites lie in the western, Indonesian part of the central range. The large populations formerly reported under Nepenthes lamii from around the mining town of Tembagapura, at about 1900 m, fall within the altitudinal range of this species. The region is large and poorly explored, so the true distribution may be wider.

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 forms have been described, and no natural hybrids are mentioned in the sources consulted. Colour, however, varies greatly. Lower pitchers are yellowish green, liberally speckled or suffused with red, or entirely red. Upper pitchers range from pale yellow with a reddish peristome to entirely reddish. Plants in full sun are usually redder and stockier than plants in forest shade. The midrib and tendrils can also turn from yellow to red under strong light.

Where and when to see it

This species grows in remote uplands of Papua where access is restricted and permits are needed. Where montane forest is accessible, look for open, light places: forest edges, old clearings, mossy scrub on ridges. Look up for the yellowish or reddish upper pitchers in the scrub, and down into the moss for the smaller lower pitchers with their distinct waist. Keep an eye on altitude: above the treeline, over 3000 m, a small red pitcher plant is probably Nepenthes lamii.

Conservation status

Assessed on the Red List as Least Concern. The species occurs on several mountains, partly in places that are hard to reach, and it tolerates disturbed and recovering vegetation. As a member of Nepenthes it is listed in CITES Appendix II, so international trade in wild plants requires a permit. Local threats are mining and its associated infrastructure in the central range, and in the longer term climate change, which shifts the altitudinal zones of mountain plants.

Scientific name

Nepenthes monticola | Robinson, Wistuba, Nerz, Mansur & McPherson, 2011

Nepenthes monticola was described in 2011 by Alastair Robinson, Andreas Wistuba, Joachim Nerz, Muhammad Mansur and Stewart McPherson, in the book New Nepenthes: Volume One (pp. 522-555), in which the authors split what had until then been considered a single species complex into two species. Several mountains in the west central highlands of western New Guinea, at 1,400-2,620 m elevation; no single specific type locality is designated. Prior to 2011, this highland species was conflated with the closely related N. lamii (golf 25), from which it was subsequently distinguished through detailed morphological study. The specific epithet derives from the Latin "monticola" ("mountain-dweller"), referring to this species' high-montane habitat.

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