Nepenthes abgracilis Jebb & Cheek, 2013

Cheek, Martin & Jebb, Matthew, 2013, The Nepenthes micramphora (Nepenthaceae) group, with two new species from Mindanao, Philippines, Phytotaxa 151 (1), pp. 25-34 : 29-31

Nepenthes abgracilis Jebb & Cheek , sp. nov.

Type :— PHILIPPINES. Mindanao, Surigao Province (not further localised), 670 m a.s.l., April 1919, Ramos & Pascasio in BS 34501 B, (holotype UC!, photo K!) ( Fig. 1 ) .

Diagnosis: — Nepenthes gracilis similis sed caulibus teretis (non triangularibus), peristomio 2–2.5 mm diametro ad marginem interiorem edentato (non ca. 0.5 mm diametro margine dentato) glandulis nectariferis in facie operculi inferiore>100 numero (non <30) distincta.

Description: — Terrestrial climber to several metres tall. Rosette and short stems unknown. Climbing stems terete, lacking wings, 6–7 mm diam., internodes 15–18 mm long, indumentum absent, apart from moderately dense minute sessile depressed-globose red glands 0.05 mm diam; stem apex unknown. Leaves spirally inserted, coriaceous, apetiolate, narrowly oblanceolate-oblong, 23.2–29 × 2.6–3.1 cm, apex attenuate, base gradually attenuate to ca. 1.3 cm wide at base, clasping the stem for 3/4 to 4/5 its circumference, at an acute angle from the vertical, forming wings 0.3–0.4 cm wide and extending 0.9–1.2 cm below the leaf axil; longitudinal nerves 3–4 pairs on each side of the midrib in the outer ¾ of the blade, arising from the leaf base and along the midrib, visible only on adaxial surface; pennate nerves not visible, upper surface dark green, lower surface drying brown, moderately densely scattered with sessile glands as the stem, hairs absent. Lower and intermediate pitcher unknown. Upper pitchers (tendrils coiled) subcylindric ca. 16.4 cm × 5.5 cm, broadest at the slightly ellipsoid base, gradually and slightly constricting to 4.1 cm wide at the centre, before dilating to 5 cm wide below the peristome, outer surface yellow-green, with sessile glands as the stem, 3–4 per mm², hairs absent except a few inconspicuous simple hairs 0.05–0.10 mm long near peristome; fringed wings reduced to ridges running the length of the pitcher. Mouth ovate, ca. 6 × 4 cm, oblique; peristome cylindric, ca. 2.5 mm wide, red, faintly lobed, to 4 mm wide, 2 ridges per mm, ridges 0.1 mm high, inner and outer edges tightly in-rolled, teeth not visible; column short, not strongly developed, with holes visible at the inner edge; lid ovate-elliptic, ca. 5.2 × 4 cm, apex rounded to truncate, base rounded at base; lower surface suffused or blotched red, lacking an appendage, but with a basal ridge (probably an artefact of drying), ca. 10 mm long, 1 mm, flat-topped; nectar glands more than 100, 95% or more monomorphic and relatively uniform in size, orbicular or slightly elliptic, 0.6–0.75(–0.9) × 0.4–0.5 mm, including a narrow rim ca. 0.05 mm wide; the basal ridge upper surface with circa 20 narrowly elliptic-oblong glands 0.75 × 0.25 mm; glands at the junction of blade with peristome, deeply sunken, lacking a rim, ca. 0.25 mm diam.; sessile glands as on stem evident only at the edge of the lid, few and inconspicuous; spur entire. Inflorescence and fruit unknown.

Distribution & habitat: — Philippines, Mindanao, Surigao Province. Forested submontane ridges, probably ultramafic, 670 m a.s.l.

Etymology:— The epithet abgracilis means ” from gracilis ” referring to the type specimen that was early identified by Merrill (see above) as a form of the species of that name.

Conservation status: — Nepenthes abgracilis is here assessed as Critically Endangered, under Criterion D of IUCN (2012). A single location is currently known (NE Mindanao). Although mining for metal ore occurs at the Mt Legaspi location, this is so far at lower altitudes than the species is known to occur ( McPherson 2009). However, recent logging in Mindanao may have resulted in the extinction in the wild of one species recently ( Cheek 2011). It is hoped that further observations will show that N. abgracilis is more common and widespread than present data suggest.

Nepenthes cid Jebb & Cheek , sp. nov. Type:— PHILIPPINES. Mindanao, Bukidnon, Dalvangan , 26 Dec. 1952, Cid 8 (holotype L!; photo.K, isotype PNH) ( Fig. 2 ).

Diagnosis:— A N. micramphora caulibus foliis ascidiisque indumentosis (non glabris), ascidiis subcylindricis plerumque in medio constrictis (non infundibuliformibus) supremis alis conspicuis fimbriatis obsitis (non carentibus).

Description:— Epiphytic shrublet high in trees, 0.1–0.5 m tall. Stems several from a woody rootstock ca. 2 × 5 × 2 cm, roots numerous, stout, 2 mm diam. Rosette shoots and climbing stems not seen, short stems terete, 3–4 mm in diameter, internodes 1.5–2.5 cm long, axillary buds not seen, moderately densely and persistent hairy in distal internodes, hairs white, covering ca. 50% of the surface, hairs 0.2–1.0 mm long, mainly simple, some with 2–6 erect branches from the base, either all equal or with a bristle hair longer than the others, intermixed with dark red depressed globose sessile glands 0.05 mm in diameter. Leaf blades chartaceous, drying brown on both sides, oblong-elliptic, (9.0–)11.5–13.0(–14.0) × (1.2–)2.2–3.0 cm, apex acute, not peltate, base decurrent, longitudinal nerves 2(–3) pairs in the outer half of the blade, arising from the base of the midrib, conspicuous on the upper surface; pennate nerves moderately numerous and conspicuous on the upper surface, more or less patent; midrib on both surfaces moderately densely hairy (ca. 20% cover) with white, simple, mostly appressed hairs 0.2–0.4(–0.5) mm long, on lower surface, 0.3–1.0 mm long, on upper surface, the leaf-blade otherwise with sparse simple hairs and moderately dense depressed globose red-black glands 0.05 mm diam. Petiole 2.5–4.0 × 0.4–0.5 cm, wings held flat or slightly u-shaped, clasping the stem for ½ its circumference, not, or very slightly decurrent, indumentum as leaf-blade. Tendril>50% covered in appressed hairs 0.25–1 mm long, hairs simple or basally branched, arms equal or with one long and bristle-like ( Fig. 2E ). Lower pitchers not seen. Intermediate and Upper pitchers (tendrils not fully coiled) subcylindrical in outline (4.5–)6.0–11.0 × 1.9–2.8 cm, often with the basal 1/2–3/5 ellipsoid, narrowing gradually and slightly about the middle to ca. 1.6 cm wide before widening slightly to the peristome, outer surface 10–30% covered in minute, 4–5-armed, stellate hairs 0.1 mm diam., mixed with sparse minute simple hairs and larger basally branched hairs 0.4 mm long, together with depressed globose glands 0.05 mm in diameter; fringed wings running from the peristome to within 1–2 cm of the base of the pitcher, 1.8–2.0 mm wide, fringed elements (0.5–)1.0(–1.5) mm long, 3–4 mm apart, held close to the pitcher surface; mouth ovate 1.1–2.1 × 1.8–2.8 cm, moderately oblique, straight to slightly concave. Peristome cylindrical 1–1.5(–2) mm wide, even in width from front to lid, 3 ridges per mm, ridges 0.10–0.15 mm high, inner edge in life inconspicuous, incurved, ( Fig. 2J ), when dissected and unrolled, with a line of holes, teeth absent ( Fig.2 L&K ), outer edge not lobed; column not developed. Lid orbicular 1.9–2.2(–2.8) × 1.8–2.0 cm, apex emarginate or rounded, base rounded or weakly cordate, lower surface lacking a basal ridge or appendage, drying brown; nectar glands more or less monomorphic and evenly and moderately distributed over the lower surface of the lid, 1.5–3 nectar glands per mm², glands large, orbicular or slightly longitudinally elliptic, borders low, rounded, (0.3–) 0.4–0.6 mm long, lacunae drying black, glossy; glands slightly denser along the midline and more diffuse at the margin; red sessile peltate or depressed-globose glands 0.05 mm diam., scattered evenly; marginal areas with minute inconspicuous branched hairs. Spur simple, tapering from base to apex, acute, 4–5 mm long, moderately to densely hairy. 10–20% covered in simple hairs 0.2 mm long. Inflorescence and Infrutescence unknown.

Etymology:—The specific epithet is dedicated to the collector of the type specimen, F. Cid (fl. 1952) of the Herbarium of the Department of Botany, University of the Philippines.

Distribution & ecology:— Philippines, Mindanao, Bukidnon; lower submontane forest, on tall trees. Elevation 770 m.

Conservation:— Nepenthes cid is currently known from one location in a country where most of the original forest habitat has been cleared for timber and agricultural land ( Myers et al. 2000) and where forest degradation and clearance are ongoing. Intensive industrial pineapple plantations extending SE along the valley from Cagayan de Oro appear to be the main pressure on natural habitat at the type locality, as viewed on GoogleEarth (viewed 2 Oct. 2013). The population found include less than ten individuals (two), so N. cid is here assessed as Critically Endangered under Criterion D of IUCN (2012). It is hoped that additional locations for this species will be found and that one or more can be protected to ensure the survival of this species. However it is a concern that despite much searching by many enthusiasts in the last 10 years, including in the Bukidnon area (e.g. McPherson 2009), this species has not been collected in the last 60 years. This span corresponds with the peak period of forest destruction in the Philippines ( Sohmer & Davis 2007). It is possible that N. cid is already globally extinct.

Notes:—Excepting for Nepenthes cid , and N. truncata Macfarlane (1911: 209) , all other species of Nepenthes known from Mindanao are mainly terrestrial, although a few can sometimes root on the base of trunks of stunted trees in mossy forest on mountain peaks. However, examples of high epiphytes such as N. cid , on tall trees in lower submontane forest (700 m a.s.l) are rarer. Potentially N. cid could be more common than the sparsity of the existing material indicates, but due to its inaccessibility on tall trees is rarely seen. Nepenthes cid remains incompletely known to science. Botanists in Mindanao are urged to search for this species to establish whether or not it survives, to reveal its full range and to obtain collections with inflorescences, thus far unknown.

Figures

FIGURE 1. Nepenthes abgracilis A habit, stem with upper pitcher; B upper pitcher (from McPherson 2009); C tendril apex (pitcher not developed), indumentum; D outer surface of pitcher, with sessile glands; E nectar glands, lower surface of lid, midline (elongated); F nectar glands of lateral areas; G nectar glands, lid margin; H peristome, inner edge dissected (non-natural state); I peristome view from above; J peristome transverse section (inner surface on right); K lid, lower surface, midline ridge (probably artefact of drying). Scalebars: single = 1 mm; graduated single = 2 mm; double = 1 cm; graduated double = 5 cm (drawn by A. Brown from the type specimen).

FIGURE 2. Nepenthes cid A habit, showing the whole plant, with woody rootstock; B lower surface of leaf-blade showing simple hairs and sessile globose glands; C stem, showing hairs; D tendril, showing hairs; E detail of D showing individual 'dagger hairs'; F outer surface of pitcher showing minute stellate hairs; G lower surface of pitcher lid; H nectar glands from midline of lid; I nectar glands from near periphery of lid; J peristome, viewed from above; L & K peristome, after dissection, rolled back to expose inner edge with holes (normally concealed); M peristome, transverse section, outer edge to right; N junction of lid and peristome, with spur. Scalebars: single = 1 mm; graduated single = 2 mm; double = 1 cm; graduated double = 5 cm (drawn by A Brown from the type specimen).