Nepenthes biak Jebb & Cheek, 2018

Cheek, M., Jebb, M., Murphy, B. & Mambor, F., 2018, Nepenthes section Insignes in Indonesia, with two new species, Blumea 62 (3), pp. 174-178 : 175-177

Nepenthes biak Jebb & Cheek , sp. nov. — Fig. 1

Differs from N. insignis Danser in the upper pitchers in frontal view slightly constricted in the middle (not funnel-shaped);stems cylindrical (not triangular in section) leaves clasping stem (not decurrent down the stem as wings to the node below). — Type: Cheek 18785 (holotype MAN; isotypes BO, K, L), 25 Aug. 2017, cultivated at RBG, Kew (2002-896) from plants donated by Robert Cantley, origin Biak Island .

Etymology. Named for the island of Biak (noun in apposition).

Terrestrial climber to at least 3 m tall, indumentum of scattered red sessile glands 0.05 mm diam, inconspicuous, on all outer surfaces, glabrous apart from the tendril and pitcher (and proba-bly the inflorescence). Rosette stems with lower pitchers only known from a photograph. Short stems not strongly differentiated from climbing stems, with internodes cylindrical 6–7 mm diam, 2.5–4 cm long. Climbing stems as short stems, internodes 5 mm diam (hydrated material), 5.8–9 cm long, axillary buds not conspicuous. Leaves of short stems spirally inserted, glossy, leathery, linear-narrowly oblanceolate, apex rounded-acute, not peltate, base gradually attenuate, broader than stem, clasping the stem for 3/5 its circumference, shortly decurrent for 2–7 mm. Longitudinal nerves 2(–3) pairs on each side of the midrib in the outer half, pennate nerves numerous, arising at c. 60° from the midrib; nerves conspicuous only in dried specimens. Leaves of climbing stems as short stems, but generally shorter and narrower 16.4–17.5(–26.5) by 2–2.9(–4.8) cm. Lower pitchers (tendril vertical, uncoiled; fringed wings) seen only in photos of seedlings in the wild – small ovoid-cylindric. Intermediate pitchers (tendril arising laterally from pitcher base, uncoiled) variable in shape and size, from those resembling the lower pitchers in being partly with fringed wings, etc. to those which are larger, resembling the primary upper pitchers. Intermediate pitchers resembling lower pitchers ovoid-cylindric 4.5–8.5 cm high, 1.8–3.5 cm wide at base, tapering to 1.4–2 cm wide below peristome; fringed wings (rarely present only in smallest pitchers) c. 1 mm wide, fringe elements c. 2 mm long, 2 mm apart. Mouth ovate, peristome green, 1.2 mm diam; lid ovate, c. 1–1.5 cm diam. Upper pitchers (mouth facing away from the coiled tendril) dimorphic and dichromic, the lowermost 2–4 (primary) larger and heavily blotched with purple over a green background, the peristome uniformly purple; the uppermost (secondary) small, almost pure yellow. Upper pitchers overall ± cylindrical in side view, gradually laterally constricted in the middle in frontal view, fringed wings absent reduced to ribs that are increasingly thickened and mechanical towards the base in lower half of the pitcher, extending as flanges around the curve of the base and up the tendril. Lowermost (primary) upper pitchers 19–23 cm high, in side view 3.2–3.6 cm wide at midlength, 3.5–4.2 cm wide near base, 4.0– 4.5 cm wide below peristome; in frontal view 2.5–2.9 cm wide at midlength, 3.5 cm wide near base, 4.0– 4.1 cm wide below peristome; ribs c. 1.7 cm apart below peristome, extending to 2.5 cm apart near base, indumentum of sparse, c. 1 % cover, of simple translucent brown 4–5-celled acute stiff hairs 0.15–0.4 mm long, mixed with red sessile glands 0.025–0.05 mm diam, about 3 % cover. Mouth ovate-elliptic 40–60 mm interior length by 23–38 mm width, oriented at 45° from the horizontal, straight, not curved until the dorsal 1/10 which is abruptly erect forming a short, ill-defined column. Peristome dark glossy purple, subcylindrical in section 5 mm wide in frontal part, 7 mm wide towards the column, outer edge undulate, rigid, with about 5 pointed, rigid lobes on each side, mainly held flat against the pitcher wall, but some patent, variable in length, 1–5 mm long, inner edge lacking teeth and directed towards pitcher wall; ridges conspicuous, 0.3–0.35 mm apart, c. 0.2 mm high; lid ovate-elliptic (3.5–)4–5.8 by (2.9–) 3–4.7 cm held about 45° above the horizontal, apex rounded-truncate, base truncate, basal appendages absent, upper surface lacking hairs but with sessile red glands on the upper surface, with a pair of low, curved ridges each side of the midline, corresponding on the lower surface with two arced bands of 80–130 nectar glands on each side of a gland-free midline band 5–6 mm wide, the marginal 5–7 mm also lacking nectar glands; nectar glands orbicular or transversely elliptic, drying purple, surrounded by a low crater-like yellow wall 0.25–0.5 mm by 0.15–0.25 mm, entire lower surface with scattered minute red globose glands 0.05 mm diam. Margin of lid width minute erect branching hairs 0.05–0.1 mm high in a dense line. Spur patent, curved downwards, dorsiventrally flattened 7.8 mm long, apex forked, the lobes acute, c. 0.5 mm long. Uppermost (secondary) upper pitchers as the primary except, 12.5–13.5 cm high, in side view 2.6–3 cm wide at middle, 2.8–3.2 cm near the base and 2.6–3 cm wide below the peristome; in frontal view 1.6–1.8 cm at middle, 2.3–2.5 cm wide near base, and 2.5–3.5 cm wide below the peristome, ribs c. 1.7 cm apart below peristome, 2.5 cm apart towards base. Mouth 36–45 mm interior length, 25–32 mm wide. Peristome yellow, 4 mm wide in frontal part, 5 mm towards column; lobes 5–7(–9) on each side; lid 3.6–4.8 by 3–4 cm. Inflorescences and infructescences unknown.

Distribution & Ecology — Limestone coastal cliffs in the lowland evergreen forest zone – sometimes epiphytic on mangrove trees. Endemic to Biak Island; sea-level.

Additional specimen. INDONESIA, New Guinea , Biak Island, near Parieri, 12 Sept. 1966, Kostermans & Soegeng-Reksodihardjo 936 ( L, http://data. biodiversitydata.nl/naturalis/specimen/ L.1852584, image viewed online) .

Conservation — McPherson (2009: 1061) states “the once widespread populations of N. insignis on Biak are severely threatened by intensive poaching by locals who sell wildcollected plants to tourists briefly visiting Biak on cruise ships. I witnessed such poaching of plants at first-hand, and believe that most of the accessible populations in Biak are severely threatened or already destroyed. Since there is no local infra- structure or government interest to protect these plants, the outlook for these unique populations on Biak is poor”.

It seems likely that N. biak should be assessed as Critically Endangered given the single location (Biak) and the threats stated by McPherson above, according to Criterion D of IUCN (2012). Biak, about 70 by 30 km in size and, with a population of over 100 000 persons, is relatively densely populated. It is reported as having been extensively logged in colonial times. Forest has also been cut down to clear land for planting ( Wikramanayake 2002: 551). Nepenthes biak has been recorded from the southeastern part, both along coastal cliffs and at least 1 km inland (e.g., Kostermans & Soegeng-Reksodihardjo 936, L). It is not known how far over the island the range of the species extends (or extended). If this species is to survive in the wild, surveys to collect such data are advisable, so that a management plan for the species might be devised. This would include aware- ness raising for the local population, a possible propagation programme to meet the demand for live plants, and measures to protect the plant at one or more sites in the wild. It is not known if the only protected area on Biak, the Biak Utara Nature Reserve, close to the bridge with Supiori Island, contains N. biak , nor in fact whether indeed the species extends to Supiori Island, or the other islands in the Kepulauan Biak (also known as the Schouten, formerly Geelvink) group, which include Numfoor. Biak lies about 150 km from the mainland.

Figures

Fig. 1 Nepenthes biak Jebb & Cheek. a. Habit, climbing stem; b. primary upper pitcher, frontal view; c. side view of pitcher mouth of b; d. secondary upper pitcher; e. intermediate pitcher; f. indumentum of exterior of upper pitcher; g. lower surface of lid; h. detail of lower surface of lid showing nectar glands; i. spurs of upper pitchers; j. view of peristome (upper pitcher), from above;k. transverse section of peristome from j; l. inner surface of peristome from j. — Scale bars: a–c, e = 5 cm; f, h, l = 1 mm; g = 1 cm; i = 2 mm; j–k = 5 mm. — Drawn by Andrew Brown from live material of Kew (accession 2002-896), subsequently preserved as Cheek 18785.