Nepenthes alzapan Jebb & Cheek, 2013

Cheek, Martin & Jebb, Matthew, 2013, Nepenthes alzapan (Nepenthaceae), a new species from Luzon, Philippines, Phytotaxa 100 (1), pp. 57-60 : 59

Nepenthes alzapan Jebb & Cheek , sp. nov.

Type:— PHILIPPINES. Luzon, “ Tayabas Prov., Mt Alzapan ”, male fl. 7 June 1925, Ramos & Edanõ 45690 (holotype K! ; isotypes NY! , UC! , US! ) ( Fig. 1 ).

Diagnosis:— A Nepenthes bellio caulibus acute trigonis atque conspicue alatis (nec teretibus nec leviter angularibus, nec alatis), ascidiis superioribus globosis, 6.5-6.8 x 4.2-5cm, (nec infundibuliformis, 7.3–7.5 × 2–2.5cm); inflorescentia masculi 31.5–42 × 1.5–2cm (nec 10–15 x 1 cm) differt.

Description:— Terrestrial climber (probably) to at least 0.4 m tall. Stems alabaster to pale browncoloured, acutely triangular in transverse section, 5(–7) mm diam., two of three angles extended into wings up to 3–4 mm wide, decurrent from the leaves, internodes 1.3–2 cm long, glabrous but with scattered sessile red -coloured glands. Leaves coriaceous, sessile, ligulate–oblong, (7–)8–13.5 × 1.5–2.5(–3.4) cm, apex acute, base clasping the stem for 2/3 its circumference, decurrent almost to the node below as a wing up to 4mm wide. Longitudinal nerves 5–7 on each side of the midrib, almost evenly scattered. Pennate nerves irregular, oblique. Indumentum as stem. Lower pitchers not recorded. Upper pitchers subglobose to globoseinfundibuliform, 6.5–6.8 × 4.2–5 cm, with moderately sparse appressed simple hairs 0.2–0.5 mm long; wings present only for 5–17 mm of the pitcher length, at the midpoint or apex, 1–2 mm wide, with fringed elements 1.5 mm apart, 3–4mm long with moderately sparse simple or basally 2–3-branched hairs 0.1–0.15 mm long; mouth suborbicular, forming the broadest part of the pitcher; peristome subcylindrical to flattened, 6–10(– 14)mm broad, ribs 1.5 mm apart, about 0.25 mm high, outer margin entire, revolute, inner margin dentate, teeth curved, 0.5–0.75 mm; lid elliptic, 2.5–2.7 × 2.2–2.3 cm, apex rounded, base truncate; lower surface lacking appendages, midline thickened and lacking nectar glands which occur only in two curved lateral bands, each with 35–110 glands, densest at base of the lid, where 3 per mm²; nectar glands slightly transversely elliptic or suborbicular 0.3–0.5 × 0.3–0.5mm, with a thin marginal rim 0.05 mm thick; sessile red-coloured glands 0.05–0.07 mm in diameter, about 4 per mm², spur not recorded. Male inflorescence 31.5– 42 × 1.5–2.5 cm, indumentum dense, completely covering the surface, hairs simple, bronze-coloured, 0.15– 0.35 mm long; peduncle 20–22.5 cm long, 3–4.5 mm diam.; rhachis 11.5–20 cm long, with partial-peduncles 80–110, 1-flowered; bracts inconspicuous, at apex of inflorescence only, about 0.2 mm long, inserted 0.3–1.5 mm from junction with rhachis; pedicels 7–8(–10) mm long; tepals red, narrowly elliptic, 3.5 × 1.5–1.8 mm, lower surface and margins completely covered in sinuous thin-walled bronze-coloured hairs about 0.1 mm long, apices round; staminal column 2–2.5 mm long, with thinly scattered ± patent copper-coloured hairs 0.25–0.35 mm long; anther-head globose, about 1.5 mm diam. Female inflorescences, infructescences and seed unknown.

Etymology: —The epithet alzapan refers to Mt. Alzapan, the type locality.

Distribution & ecology: — Philippines, Luzon, Sierra Madre Mts., Mt Alzapan, submontane mossy forest, 1800 m a.s.l.

Conservation: — Nepenthes alzapan is known only from three individuals at most, at a single location on an island which has seen high-levels of habitat-loss in the twentieth century ( Sohmer & Davis 2007). The species appears not to have been seen alive since 1925, and may already be extinct as is thought to be the case with N. robcantleyi Cheek (2011: 678) . Nepenthes alzapan is here assessed as Critically Endangered under IUCN (2001), Criterion D. It is to be hoped that the species will be rediscovered at the type location and perhaps additional locations and that it will not prove to be so rare or as threatened as existing data suggest. However Sohmer & Davis (2007) document two other species, Psychotria alzapaniensis Sohmer & A. Davis (2007: 123) and Psychotria longissima Quisumbing & Merrill (1928: 206) which are also known only from Ramos & Edanõ type specimens made in 1925 at the same location. Both species they assess as Critically Endangered, if not extinct ( Sohmer & Davis 2007).

Figures

FIGURE 1. Nepenthes alzapan A habit, with upper pitcher and male inflorescence; B transverse section of stem at base of leaf insertion; C hairs on outer pitcher wall; D lid of upper pitcher, lower surface; E nectar glands from lower surface of lid; F peristome, view from above; G peristome, inner edge, showing teeth; H peristome, transverse section, inner edge to right; I detail of fringed wings of upper pitchers; J male flower; K rhachis indumentum; L tepal indumentum, outer surface.A–E & J–L from Ramos & Edanõ in BS 45690 (NY); F–I from Ramos & Edanõ in BS 45690 (K). Scale bars: single=1 mm; graduated single bar = 2 mm and 3 mm; double = 1 cm; graduated = 5cm. All drawn by ANDREW BROWN.