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Nepenthes abgracilis
In April 1919 the Filipino botanists Maximo Ramos and his colleague Pascasio collected a pitcher plant in what was then Surigao province, in north-eastern Mindanao. Elmer Merrill, at the time the authority on the Philippine flora, saw in it a form of Nepenthes gracilis, the widespread lowland species of Borneo and Sumatra. Almost a century later Martin Cheek and Matthew Jebb recognised the sheet in the Berkeley herbarium as a species of its own, and named it after that mistake: abgracilis, 'away from gracilis'.
No photograph of this species under a Creative Commons licence or in the public domain is in the guide yet.
Identification
A climber with a round, wingless stem six to seven millimetres thick and short internodes. The leaves are sessile, leathery, narrowly oblanceolate to oblong, 23 to 29 cm long and only 2.6 to 3.1 cm wide; the base clasps the stem. Only the upper pitchers are known: almost cylindrical, about 16.4 cm tall, broadest at the slightly ellipsoid base at 5.5 cm, gradually narrowing to 4.1 cm at the middle and widening again to 5 cm below the peristome. The peristome is round, about 2.5 mm wide, red, with two ridges per millimetre and an inner margin without teeth. The lid is ovate-elliptic, about 5.2 by 4 cm, suffused red beneath with a narrow ridge at the base, and bears over a hundred round nectar glands. Lower and intermediate pitchers, inflorescences and fruits are unknown.
Similar species
The species Merrill confused it with, Nepenthes gracilis, has a three-angled stem, a very narrow peristome of about half a millimetre with a toothed inner margin, and fewer than thirty nectar glands under the lid. Nepenthes gracilis does not occur in the Philippines in any case. Within the group around Nepenthes micramphora, where the authors placed it, Nepenthes abgracilis is the largest; Nepenthes micramphora itself has small funnel-shaped pitchers and a branched spur, and Nepenthes cid is a hairy dwarf with pitchers of at most eleven centimetres.
The trap and how it works
A pitfall of the upper-pitcher kind: hanging from a tendril, with a narrow, round, red rim and a large lid shielding the mouth. The lid is the most striking component: with over a hundred nectar glands on its underside, round to slightly elliptic and half a millimetre to almost a millimetre across, it offers far more lure than the bare lid underside of Nepenthes gracilis. The peristome is tightly rolled at both edges. Whether the upper pitchers catch mainly flying insects or also ants walking up the stem has not been studied for this species.
Habitat and ecology
The label records forested submontane ridges at 670 m, probably on ultramafic rock (B1, R3). North-eastern Mindanao and its offshore islands form one of the largest ultramafic areas in the Philippines, with a pitcher-plant flora of its own: Nepenthes merrilliana, Nepenthes mindanaoensis and Nepenthes truncata occur there. Whether Nepenthes abgracilis is strictly tied to ultramafic soil is unknown.
Distribution and elevation
Endemic to Mindanao, and known only from the type collection from the former province of Surigao, now split into Surigao del Norte and Surigao del Sur. The 1919 label names no mountain. Later summaries link the site to Mount Legaspi in north-eastern Mindanao, but that mountain could not be found in the part of the description available for this guide; the 'Mt. Legaspi' in our species list should therefore be regarded as unconfirmed.
- Native
Forms and variation
For a species resting on a single herbarium sheet no variation is known. The description notes that over 95 per cent of the nectar glands under the lid are of one type, which also characterises the species within the micramphora group. No hybrids are known; there is simply too little material to say anything about them.
Where and when to see it
There is no place where this species can be found with certainty. Anyone walking forested ridges around 600 to 700 m in north-eastern Mindanao can look out for a climbing pitcher plant with long, narrow leaves and slender, almost cylindrical pitchers with a thin red rim. A well-documented record, with photographs of the underside of the lid, would be the first living find and is valuable to science; leave the plant where it is and report the find to a Philippine herbarium.
Conservation status
The species has not yet been assessed by the IUCN (Not Evaluated). The authors rated it Critically Endangered: one site is known, in a part of Mindanao where large-scale nickel mining takes place on ultramafic ground. It has not been collected since 1919. Like all Nepenthes it is listed in CITES Appendix II.
Scientific name
Nepenthes abgracilis | Jebb & Cheek, 2013
Described by Martin Cheek and Matthew Jebb in 2013, in Phytotaxa, based on a holotype collected in April 1919 in the former Surigao Province, Mindanao, Philippines, at 670 metres altitude. The type locality lies in the former Surigao Province, on the island of Mindanao, Philippines. The name "abgracilis" means "of/like gracilis" and refers to an early misidentification by the botanist Elmer Drew Merrill, who initially classified a herbarium specimen of this species as Nepenthes gracilis.
World Checklist of Vascular Plants (WCVP), via Plants of the World Online (POWO), Royal Botanic Gardens, Kew.