Nepenthes kitanglad 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 : 10-13

Nepenthes kitanglad Jebb & Cheek sp. nov.

urn:lsid:ipni.org:names:77134487-1

Fig. 2

Diagnosis

Differs from N. saranganiensis Sh.Kurata in having angled, (not winged) stems, lower and upper pitchers strongly dimorphic, (not subdimorphic); in being a climbing epiphyte of forest (not a terrestrial shrub of open areas) and in having a strongly concave pitcher mouth with a long neck (not with the pitcher mouth flat or only slightly concave, lacking a neck).

Etymology

Named, as a noun in apposition, for Mt Kitanglad, the type and only known locality of the species.

Type

PHILIPPINES. Mindanao, Bukidnon Province, Intavas, Impasug-ong, Mt Kitanglad, 18 Jul. 1991, Gaerlan, Sagcal & Fernando in PPI 3274 (holotype BISH!; isotype BRIT!).

Description

Epiphytic climber, probably 1 m tall or more. Short stems terete, 4–5 mm diam., internodes ca. 6 cm long, axillary buds not evident; surface glossy, appearing glabrous but with extremely sparse brown, simple hairs ca. 0.5 mm long, glabrescent. Climbing stems strongly 4-angular, 7–9 mm diam., internodes 11–12 cm long; indumentum as short stems. Leaves of short, and of climbing stems more or less identical, thickly papery; blade oblong-elliptic, 15.5–33 × 4.3–7 cm; apex acute, not peltate, tendril arising abruptly; base cuneate, decurrent to petiole; longitudinal nerves 3–4 pairs, conspicuous in the marginal half on the upper surface; pennate nerves arising at about 45° from the midrib, irregular, reticulate, branching in the marginal half; drying brown-black above, matt mid-brown below, appearing glabrous apart from margin but with indumentum as stem, densest on midrib but soon glabrescent; lower surface with sessile depressed-globose red-black glands ca. 0.05 mm diam.; margin densely fringed with soft fine orange-brown patent simple or bifurcate hairs 1 mm long. Petiole evenly winged along its length, 4–5 × 0.4–0.9 cm, wings patent; at base clasping the stem for ⅔ to ¾ of its circumference, decurrent diagonally as a narrow wing, in short stems 7 mm long, in climbing stems 18 mm long, and continuing as a ridge to the node below. Lower pitchers narrowly ovoid-cylindric, 12.5 cm tall, 5 cm broad, widest in the basal half, narrowing steadily to ca. 3 cm wide below the peristome; outer surface 10–25% covered in pale brown hairs of two types, (1) bushy brown hairs 0.1–0.25 mm long and wide, with 4–8 arms ascending from a short central axis, 7–12 per mm 2, (2) long brown straight erect hairs 1.5–1.75 (–2.5) mm long, with 2–4 short branches ascending from along the length of the main axis, sparse; fringed wings, 2–4 mm wide, running 3–4 cm from peristome towards base of pitcher, then diminished to slender ridges, wings extended over the peristome by two foliose flaps 3–4 × 3–4 mm, fringed elements 4–5 mm long, 2.5 mm apart (1.5 mm apart on foliose flaps); mouth ovate-lanceolate, highly oblique, concave, ca. 4.1 × 2.8 cm; column developed, tapering towards lid ca. 9 mm long, 2.5 mm wide at midpoint; peristome subcylindric, 1 mm wide at front of pitcher to 3 mm wide at sides, ridges ca. 2.5 per mm, ridges 0.1 mm high, inner edge lacking conspicuous teeth or holes, outer edge not lobed. Lid narrowly ovate to rhombic 3.5 × 2.3 cm, apex rounded, base rounded to truncate, lower surface lacking a basal appendage, but with a low basal ridge 10 mm long, 0.5–1 mm high, extending from the junction with the peristome; nectar glands small and sparse, 6–8 on each side of the midline which mainly lacks glands, absent from basal ridge, nectar glands monomorphic, slightly perithecoid, orbicular or slightly elliptic, 0.25(–0.35) mm long, mixed with denser sessile depressed-globose, red-black glands, 0.05– 0.1 mm diam., 8 per mm 2; marginal 2–3 mm of lower surface with minute stellate hairs densest near margin; upper surface with same indumentum as outer pitcher surface, but long hairs rarely seen. Spur not seen. Upper pitchers (tendril coiled) ovoid-cylindric, green, slightly maroon above, 21.5 × 6.5 cm, widest in the ovoid basal third, narrowing to ca. 5 cm wide in the cylindrical upper part; outer surface with same indumentum as lower pitcher; fringed wings reduced to ridges apart from two foliose flaps immediately below peristome, point of attachment 3–4 mm long, angular-elliptic, 9 × 6 mm, bearing fringes 2–7 mm long; mouth ovate-lanceolate 7 × 4 cm, oblique, concave, the frontal part straight; column ca. 1.5 × 0.8 cm; peristome rounded-flattened, 1.75–5.5 mm wide, widest at sides, ca. 1.75 ridges per mm, ridges 0.1 mm high, inner edge lacking conspicuous teeth or holes, outer edge not lobed. Lid ovate-triangular, 5 × 3.8–4.2 cm, apex rounded, base truncate; lower surface with a weakly developed, convex basal appendage 1.5 mm high, arising from a low basal ridge 7 mm long; nectar glands ca. 16 on each side of the midline, sparsely scattered, more or less absent from midline, but present at appendage, nectar glands orbicular or slightly elliptic, slightly or strongly perithecoid, 0.25–0.5 × 0.25–0.45(–0.75) mm; sessile glands 0.05–0.1 mm diam., 8–20 per mm 2; upper surface of lid with indumentum as outer surface of pitcher. Spur inserted 2 mm below junction of lid and pitcher, pointing downwards, terete, 17 × 0.9–1 mm, dilating to the 1.8 mm wide rhombic-acute apex, indumentum moderately dense of long patent simple hairs as on the pitcher outer surface. Male and female inflorescences unknown.

Distribution and habitat

Philippines, Mindanao, Bukidnon Province, known only from Mt Kitanglad; epiphytic in mossy forest, geology volcanic, elevation 1800–2100 m.

Conservation

Here N. kitanglad sp. nov. is assessed as Critically Endangered since it is known from only a single location, Mt Kitanglad, on an island which has seen extensive forest clearance for logging and agricultural expansion in recent years ( McPherson 2009: 759). For these reasons one species, N. robcantleyi Cheek is already suspected to be extinct in the wild ( Cheek 2011). Nepenthes kitanglad sp. nov. is not a spectacular or especially bizarre species so is unlikely to come under pressure of collection for the horticultural trade which has brought several species of the genus close to extinction.

Remarks

McPherson (2009: 755–759; figs 417 & 418) depicts from volcanic Mt Kitanglad in N-Central Mindanao a plant under the name of N. saranganiensis Sh.Kurata ( Kurata 2003: 41) . Yet, the Kitanglad plants he depicts differ from N. saranganiensis as depicted in its protologue in habit, habitat and in morphology. In 2013 sheets of Gaerlan et al. in PPI 3274 (BISH, BRIT) became available from Kitanglad.These matched McPherson’s (2009) depiction, enabling a detailed comparison to be made with N. saranganiensis . The conclusion is that the Kitanglad material represents a different species from N. saranganiensis and is here described as N. kitanglad sp. nov. Differences between the two taxa are given in Table 2.

N. kitanglad sp. nov. is unusual in the N. alata species group ( Cheek & Jebb 2013d) in the strongly concave mouth of the upper pitchers, in which the base of the lid is held over the mouth. It is also unusual in that the rear of the peristome narrows to a neck, forming a moderately well-defined column for the lid. Within the N. alata group, these two features are otherwise currently known only in N. hamiguitanensis Gronem., Wistuba, V.B.Heinrich, S.McPherson, Mey & V.B.Amoroso ( Gronemeyer et al. 2010), but that species is restricted to ultramafic Mt Hamiguitan in SE Mindanao and differs greatly in the shape of the upper pitchers which are stout, widest at the midpoint, with a funneliform lower half narrowing to a more slender, cylindrical upper half. It is possible that N. hamiguitanensis , N. kitanglad sp. nov. and N. saranganiensis are related since all have angled stems (or in the case of the last species, winged), a feature otherwise unknown in the otherwise terete-stemmed N. alata group. Nepenthes kitanglad sp. nov. is unique in the N. alata group in its lid posture, as seen from photographs and herbarium specimens. The lid is held at ca. 45° below the horizontal, largely concealing the mouth. In other species it is usually elevated above the horizontal, sometimes by ca. 45° ( N. saranganiensis ) or as much as 90° or more ( N. graciliflora Elmer ). So far, N. kitanglad sp. nov. is the only species of Nepenthes recorded from Mt Kitanglad.

Figures

Fig. 2. Nepenthes kitanglad sp. nov. A. Habit, climbing stem with upper pitcher (from herbarium specimen). B. Upper pitcher (from live plant). C. Lower pitcher. D. Indumentum from leaf margin. E. Indumentum from tendril. F. Indumentum from stem (extremely sparse hairs). G. Indumentum of outer pitcher surface, plan view. H. Ibid., profile view. I. Lower surface of lid (upper pitcher). J. Detail of glands from lower surface of lid. K. Spur of upper pitcher. L. Peristome, upper pitcher, view from above. M. Peristome, view from inside of pitcher, showing minute teeth. N. Peristome, transverse section (outer surface on right). A, D–N from Gaerlan et al. in PPI 3274 (BISH); B from McPherson (2009: Fig 417); C from Gaerlan et al. in PPI 3274 (BRIT). Scale bars: double = 1 cm; double graduated = 5 cm; single = 1 mm; single graduated = 2 mm. All drawn by Andrew Brown.