Nepenthes biak

Nepenthes biak

Synonymy

Nepenthes biak Jebb & Cheek in Blumea 62: 174 –178, fig. 1. 2018 sec. Cheek & al. 2018
    • 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.

Description

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 probably 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.A

Conservation

It seems likely that N. biak should be assessed as Critically Endangered given the single location (Biak) and the threats stated by McPherson (2009: 1061), according to Criterion D of IUCN (2012).A

Distribution (General)

Indonesia, Papua, Biak Island. Endemic.A

Etymology

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

Habitat

Limestone coastal cliffs in the low- land evergreen forest zone – sometimes epiphytic on mangrove trees; sea-level.A

Bibliography

A. Cheek, M.R., Jebb, M.H.P., Murphy, B. & Mambor, F. 2018: Nepenthes section Insignes in Indonesia, with two new species. – Blumea 62: 174-178

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
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.
Citation: No Citation available. This specimen either has no or multiple field units.