Nepenthes kurata Jebb & Cheek, 2013

Cheek, Martin & Jebb, Matthew, 2013, Recircumscription of the Nepenthes alata group (Caryophyllales: Nepenthaceae), in the Philippines, with four new species, European Journal of Taxonomy 69, pp. 1-23 : 6-9

Nepenthes kurata Jebb & Cheek sp. nov.

urn:lsid:ipni.org:names:77134486-1

Fig. 1

Diagnosis

Differs from N. mindanaoensis Sh.Kurata in the petiole wings patent (not involute), the hairs of stem, midrib and leaf-edge bushy, 0.1 mm long, not bristle-like 1–1.5 mm long; the lid about half as long as the mouth, lid base rounded or truncate (not about as long as the mouth, base cordate).

Etymology

Named as a noun in apposition for Shigeo Kurata, whose book on the Nepenthes of Mount Kinabalu ( Kurata 1976) inspired interest in the genus among its many readers, and whose descriptions of Nepenthes are models of detail, precision and clarity.

Type

PHILIPPINES. Mindanao, “Prov. of Misamis, Mount Malindang”. May 1906, Mearns & Hutchinson in Forest Bureau 4632 (holotype K!; isotype PH!). Fig 1 .

Synonym

Nepenthes alata Blanco var. ecristata Macfarlane , Nepenthaceae . In: Engler A. (ed.) Das Pflanzenreich Heft 36, 4, 3: 72 (1908). – Type: lectotype, designated here: Philippines, Mindanao, “Prov. of Misamis, Mount Malindang”, May 1906, Mearns & Hutchinson in Forest Bureau 4632 (lecto-: K!; isolecto-: PH!).

Description

Terrestrial shrub-climber, height unknown. Climbing stems terete to slightly angular, 4–6 mm diam.; internodes 30–50 mm long; axillary buds not evident; indumentum inconspicuous, persistent to the fifth internode from the apex, hairs translucent brown, simple or 2–3-armed from the base, hairs straight, variously angled from the horizontal, ca. 0.1 mm long, covering ca. 5% of the surface except the axils (100% coverage) surface brown-black, matt. Leaves of rosette shoots thinly coriaceous, blade narrowly elliptic, 8–9 × 2–2.5 cm; apex and base acute; longitudinal nerves 1–2 pairs, within 2 mm of the margin, moderately conspicuous on both surfaces; pennate nerves at 90° from the midrib, numerous and moderately conspicuous; upper surface drying glossy pale brown, lower surface matt, mid-brown. Leaves of climbing stems as the rosette leaves, but blades suboblong or oblong-lanceolate 10–12.5 × 3.2–3.8 cm; apex obtuse or acute; base obtuse; lower surface with sessile red glands ca. 0.5 mm diam.; midrib 40–60% covered in patent, brown, simple or basally bifurcate-trifurcate hairs 0.1–0.3(–0.5) mm long; margin fringed, in young leaves, with hairs 0.25 mm long, pale-brown, 1–4-armed from the base. Petiole winged-canaliculate, 4–5 × 0.7 cm, wings patent; base clasping the stem for ⅓ to ½ its circumference, sometimes decurrent as an obtuse ridge to the node below. Lower pitchers unknown. Intermediate pitchers (tendrils uncoiled: Mearns & Hutchinson 4632) 12.5–17.2 cm long, ellipsoid in the basal third to half, 4–5.7 cm wide, constricted, more or less abruptly, 5–7.5 cm from the base into the subcylindrical upper part, 2.1–3 cm diam. dilating slightly towards the apex 3–4 cm diam.; outer surface strongly reticulated with raised nerves when dry, 2–5% covered in hairs of two types ( Fig. 1D ), (1) large erect hairs 0.3–0.75 mm long, with a single, major, curved arm, and 1–2 much smaller erect arms, and (2) minute, 3–6-armed stellate hairs 0.05–0.1 mm diam., which are more frequent, (ca. 4 per mm 2); surface covered throughout (6–10 per mm 2) with sessile, depressedglobose glands 0.1–0.2 mm diam.; fringed wings reduced to ridges except in the ca. 25 mm below the peristome, widening to 3 mm broad, with fringed elements 2.5 mm long, 2–5 mm apart; mouth oblique, suborbicular, ovate, 3–4.8 × 2.7–4.5 cm; apex with a column 9–10 mm long; peristome rounded to slightly flattened, 2–2.5 mm wide, more or less even in width, ribs 0.25–0.5 mm apart, conspicuous, about 0.1 mm high, outer edge lacking lobes, inner edge with very short teeth and conspicuous holes, teeth <0.1 mm long. Lid much smaller than the mouth, ovate, or broadly ovate, 25–35 × 25–30 mm, apex rounded to obtuse, base rounded to truncate; lower surface with a low basal ridge ca. 1 mm high, 7–10 mm long, either lacking a protruding appendage entirely ( Fig. 1F ) or with a modestly developed appendage 1–2 mm high ( Fig. 1H ); nectar glands only slightly dimorphic, (1) midline nectar glands sparse, longitudinally elliptic, 0.5–0.7 × 0.1–0.25 mm, with a thin marginal rim ( Fig. 1J ), (2) outside the midline nectar glands circular ( Fig. 1K ), sparse, <1 per mm 2, only 35–50 on each side of the midline, the largest scattered in the distal half, 0.5 mm diam., grading down to those of the marginal equatorial areas ca. 0.25 mm diam., and those at the attachment point with the peristome and the basal ridge and appendage, 0.15 mm diam.; sessile depressed-globose minute red glands 0.1–0.2 mm diam. are scattered over the surface at a density of 3–8 glands per mm 2; minute inconspicuous stellate hairs ca. 0.075 mm diam. occur in an uneven, 0.5–1 mm wide band, near the margin widening to 1.5 mm wide at the lid apex. Spur unbranched, curving downwards, stout at base and tapering to a slender apex, ca. 5 mm long, with scattered long, subpatent hairs 0.3–0.7 mm long ( Fig. 1I ). Upper pitchers (tendril coiled, Gaerlan et al. in PPI 10914) resembling the intermediate pitchers, but fringed wings 1–2 mm wide, fringed elements 2.5 mm long, (2–) 4–5 mm apart, dilating to 4.5 cm below the mouth; pitcher green, peristome maroon. Lid broadly ovate to suborbicular 32 × 35 mm, lower surface with a basal ridge 9–10 mm long, ca. 2 mm high, bearing a central, symmetrical, protruding appendage 2 × 3 mm; nectar glands denser, ca. 110 on each side of the midline. Male and female inflorescences and infructescences unknown.

Additional material

PHILIPPINES. Mindanao, Prov. Misamis Occidental, S.E. slopes of Mt. Malindang, Lake Duminagat, May 1993, Gaerlan, Sagcal & Romero in PPI 10911 (BRIT!).

Distribution, habitat & phenology

Philippines, Mindanao; evergreen forest, volcanic substrates. Elevation: ca. 1400 m.

Conservation status

Nepenthes kurata sp. nov. is here assessed as Critically Endangered under Criterion D of IUCN (2012) since currently only two individuals, probably at a single location (as currently defined by IUCN) are known. This site, the ca. 6 ha crater Lake Duminagat, is within the ca. 50,000 ha Mt Malindang Range Natural Park of which at least 20,000 ha has been cleared for cultivation purposes, but which is a tentative World Heritage Site (http://whc.unesco.org/en/tentativelists/5029/, downloaded 16 July 2013). In 2012 the Park was designated as an ASEAN Heritage Park (http://news.pia.gov.ph/index. php?article=1451343449808, downloaded 16 July 2013). It is to be hoped that further investigation will discover additional individuals and locations for this species, decreasing its threat status, and increasing the likelihood that it can be protected.

Since the terrain of Mt Malindang is reported as being rugged, with much forest surviving, there is every reason to hope that the species survives there, unlike Nepenthes robcantleyi Cheek ( Cheek 2011) also from Mindanao, which is already suspected to be extinct in the wild due to the almost total clearance of forest habitat at the single known wild location due to logging ( Cheek 2011).

Remarks

The first Nepenthes taxa described from Mindanao, both of the N. alata group, ( Cheek & Jebb 2013d), were N. alata var. ecristata Macfarl. ( Macfarlane 1908) , based on Mearns & Hutchinson 4632 from Mt Malindang, and N. copelandii Macfarl. ( Macfarlane 1908) from Mt Apo.

The first of these we here elevate to species level as N. kurata Jebb & Cheek sp. nov. Previously we had considered this taxon to be synonymous with N. mindanaoensis Sh.Kurata ( Kurata 2001) ( Cheek & Jebb 2013d). The two taxa do have similarities in the overall shape of the upper pitchers, the weakly to moderately developed basal lid appendage and the sparse nectar glands of the lower lid surface. However they can be distinguished using the characters in Table 1 . The number and extent of these features merit elevation from varietal to specific-level recognition in our opinion. Although the type specimen has rosette stems and intermediate pitchers only, a second specimen, with climbing stems and upper pitchers, Gaerlan et al. in PPI 10911 came to light recently. It is from the type locality and matches the type in essential details. Nepenthes kurata sp. nov. has the spot character within the Nepenthes alata group of a small, more or less orbicular lid, only about half the length of the pitcher mouth.

Macfarlane (1908) characterised his N. alata var. ecristata by the lid appendage being either reduced or absent; the nectar glands being few, medium to large in size, and irregularly dispersed. Of the single specimen cited (Mearns & Hutchinson 4632), only two sheets ( PH and K) have been found, both annotated in Macfarlane’s hand, each with two intermediate pitchers. Although all four pitchers share a basal ridge ( Fig. 1 F–H), only one of the four has an appendage, and that is only moderately developed as a convex emergence from the basal ridge ( Fig. 1H ). However a recent collection (Gaerlan et al. in PPI 10977) with upper pitchers, does show a developed appendage ( Fig. 1E ), suggesting the epithet ecristata “lacking a crest” is inappropriate. In any case, the Code demands priority only at one rank, so there is no requirement to adopt the varietal epithet at specific level, for which reason Macfarlane’s taxon is renamed as N. kurata sp. nov.

The upper pitchers also differ from the intermediate pitchers in the greater density of the nectar glands on the lower surface of the lid. However the shape, distribution and size of the nectar glands remain similar.

This is the only known species of Nepenthes from Mt Malindang at this time, and it is therefore the most westerly known species of the genus in Mindanao. Nepenthes kurata sp. nov. is still incompletely known, full details on its ecology, altitudinal range, population density, inflorescences and infructescences, and ethnobotany remain to be discovered.

The type specimens were collected by Major E.A. Mearns and W.J. Hutchinson in 1906 on the first recorded ascent of Mt Malindang, a volcanic mountain in the NW of Mindanao. Both sheets are annotated in the hand of Macfarlane as “ N. alata var. ecristata Macfarlane ”, and either could be selected as lectotype of that name. The K sheet is accordingly selected.

Figures

Fig. 1. Nepenthes kurata sp. nov. A. Habit, climbing stem with upper pitcher. B. Indumentum of midrib, lower surface of leaf-blade. C. Indumentum of tendril. D. Indumentum of outer pitcher surface. E. Lid, lower surface, showing nectar gland distribution on right (upper pitcher). F–G. Profiles of basal lid ridges, without appendage (F), with appendage weakly developed (G), and moderately developed (H). I Spur of intermediate pitcher. J. Longitudinally elliptic nectar glands of lid midline. K. Orbicular nectar glands of lid, outside the midline. L. Peristome from above, short teeth and holes discernible. M. Peristome viewed from inside pitcher. N. Peristome transverse section, outer surface to right. A–E, J & K from Gaerlan et al. PPI 10911; F–I, L–N from Mearns & Hutchinson 4632. Scale bars: single = 1 mm; graduated single = 2 mm; double = 1 cm; graduated double = 5 cm. All drawn by Andrew Brown.