Nepenthes halmahera Cheek, 2015

Cheek, M., 2015, Nepenthes (Nepenthaceae) of Halmahera, Indonesia, Blumea 59 (3), pp. 215-225 : 217-220

Nepenthes halmahera Cheek , sp. nov. — Fig. 1

Similar to N. danseri Jebb & Cheek of Waigeo Island, Raja Ampat Islands, Indonesian New Guinea, differing in the bracteate inflorescences, male peduncles 1.7–5.5 cm long (not ebracteate, male peduncles 10 cm long); upper pitchers without visible peristome teeth (unless distorted) and with hairs scattered over the whole surface (not with short teeth visible and lacking hairs except in the area of the spur). — Type: De Haan 1718 (holotype K; isotypes A n.v, BISH n.v, BO n.v, CAL n.v, L, LAE n.v, NSW n.v, P n.v, PNH n.v, SING n.v), Indonesia, N Maluku Province, Halmahera, Weda, Nucifera , male infl., 25 Aug. 1949.

Etymology. Named for the island of Halmahera on which it occurs, as a noun in apposition.

Terrestrial climber, 2–5 m tall. Stems terete. Rosette shoots not seen. Short shoots (Mahroji & Gushilman 211) 6–7 mm diam, internodes c. 1.5 cm long, densely covered in red depressed-globose glands 0.05 mm diam, c. 5–10 per mm 2, hairs absent. Climbing stems 3–4(–6) mm diam, internodes 1–5.5(–9) cm long, axillary buds not conspicuous, indumentum of sessile depressed-globose glands c. 0.03 mm diam mixed with very sparse simple golden-brown hairs 0.5 mm long, or hairs absent. Leaves of short shoots elliptic to lanceolate, 16.5–22.5 by 4.3–6.2 cm, apex acute, base decurrent. Longitudinal nerves 6–7 pairs, evenly scattered, inconspicuous, most visible on adaxial surface. Pennate nerves inconspicuous; margin glabrous or with sparse brown simple hairs 0.3–0.4 mm long, upper and lower surfaces entirely glabrous; or with appressed sparse hairs 0.5–0.75 mm long near the midrib of lower surface. Petiole canaliculate-winged, 2.7–3.5 cm long, 0.5 cm deep, shortly sheathing the stem and clasping the stem its entire circumference. Leaves of climbing stems elliptic, 8–15(–17) by 1.5–3.5(–4.8) cm, apex acute, base decurrent. Longitudinal nerves 5–8 pairs, conspicuous only on younger leaves. Pennate nerves numerous, patent. Indumentum absent from upper and lower surfaces, except for sessile depressed-globose glands and for the distal midrib with a few short simple hairs, sometimes the lower midrib also with simple golden-brown hairs; margin glabrous or with sparse simple patent hairs c. 0.5 mm long. Petiole canaliculate-winged, 1.5–3.4 by 0.3 cm, base clasping the stem for the 2/3s to the entire circumference, dilating abruptly as patent wings 2 mm wide around the stem, not or shortly decurrent by 0 –5 mm, the margin with sparse patent simple hairs. Tendril 9–10 cm long. Lower pitcher (short shoots) ellipsoid-cylindric, c. 11 by 3.6 cm, the ellipsoid base gradually constricting into the more slender cylindric upper portion, 2.2 cm wide at the mouth; fringed wings c. 1.2 cm apart, 0.7 cm wide at the pitcher base, fringed elements 1.5–2 mm long, 0.2–1.1 mm apart; outer surface of pitcher 10–20 % covered in inconspicuous simple pale brown hairs 0.5 mm long, mixed with dense depressed-globose red glands 0.05 mm diam, 15–20 per mm 2; mouth narrowly ovate, concave, strongly oblique, inner surface waxy, greenish white; peristome subcylindric, 1.5–2 mm wide, ribs 0.8 mm apart, weakly developed and differentiated, outer edge entire, inner edge with teeth inconspicuous, mainly concealed, 0.5 mm long, curved; column area not visible (due to specimen mounting); lid obovate-elliptic, c. 3 by 2.4 cm, apex rounded, base abruptly and inconspicuously cordate, upper surface with indumentum as outer pitcher, hairs short overall, but dense, longer, white and matted near the base; lower surface not visible (due to specimen mounting); spur bifurcate, stout, 1.5 mm wide at base, 2 mm long, branches 1 mm long, apices acute, indumentum as on lid base. Upper pitchers (climbing stems), green, ovoid-cylindric (5.8–)8.2–10.5(–11) by (2.2–)2.4–3.3(–3.9) cm, the basal ovoid portion extending (2.3–)3.2–4.7(–5) cm from the pitcher base, the ‘hip’ weakly developed, the upper cylindrical portion gradually contracting to the narrowest part 1.4–2.2(–2.7) cm wide, just above the midpoint of the pitcher, then slightly dilating to (1.3–)1.4–2.7(–3) cm wide just below the peristome; wings reduced to ridges <1 mm wide, 0.8–1 cm apart; indumentum of outer surface 5–10 % covered with golden-brown appressed acute simple hairs, 0.25(–0.5) mm long, mixed with sessile red depressed-globose glands 0.03 mm diam; mouth ovate, concave, oblique, inner surface pale glaucous waxy greenish white, with red spots; column not developed; peristome cylin- drical-flattened in transverse section (1–)1.5–2.5(–3.0) mm wide; ridges 0.3–0.35 mm apart, developed as low, blade-like wings 0.25 mm deep on the outer surface, ribs not prominent on the inner surface; the outer edge lacking lobes or with one ill-defined lobe, inner edge usually with teeth inconspicuous, occasionally (e.g. when distorted by pressing) with 0.1–0.15 mm long curved teeth visible; lid ovate-elliptic (1.2–)1.8–2.6(–2.7) by 1.4–2(–2.4) cm, apex rounded, base rounded and abruptly and shallowly cordate, upper surface with indumentum as outer pitcher,lower surface without appendages;nectar glands 25–30, scattered in the centre, especially along the base of the midline where linear-elliptic, otherwise elliptic or orbicular, 0.75 by 0.5 mm, thickly bordered, the borders glossy yellow, slightly raised, central aperture orbicular, 0.25–0.3 mm diam, dark brown; marginal 1–2 mm of lid lacking nectar glands,but with dense sessile red depressed-globose glands (10–15 per mm 2), becoming rapidly less dense away from the margin, and almost absent in the centre of the lid; marginal 0.5 mm with dense minute, bushy, branched hairs 0.07–0.08 mm long. Spur oblong, 1–1.2 by 1 mm, strongly dorsiventrally flattened and often recurved, apex rounded. Inflorescences terminal on main axis or (Bangun et al. 267, 637, 812, Phillipson et al. 6450, all MO) on short axillary spur shoots. Male inflorescences at least 2–3 on each flowering stem, separated from each other by 2–6 nodes, 9.8–19 by (1.8–)2–2.5(–3) cm, peduncle (1.7–)3–4.7(–5.5) cm long, (0.1–) 0.15 cm diam at base; partial-peduncles 30–74, 3–4(–5)-flowered in the proximal 1/2 to 2/3s, the distal part 2-flowered; bract filiform, patent (0.5–) 1–2 mm long, rarely absent, inserted variably between base and apex; partial-peduncles 1–5 mm long; partial-rhachis 0–2 mm long; pedicels 2.5–5(–6) mm long; indumentum of appressed simple, golden-brown hairs 0.15–0.25(–1) mm long, mixed with sessile depressed-globose red glands 0.03 mm diam, covering c. 80 % of the peduncle when young, but at length glabrescent, rhachis and partial-peduncles 50–60 %, covered in hairs up to 0.5 mm long. Perianth tepals 4, green, drying brown, proximal 1/10th connate, elliptic-oblong, c. 2 by 1.75 mm, upper surface with 10–15 nectar glands, confined to the proximal 1/3 to 1/2, orbicular to elliptic, minute, 0.02–0.03 mm long, sparse, separated by c. 0.25 mm, in dried material situated at apex of irregular convexities; distal part of tepal glabrous; margin with a fringe of patent hairs, lower surface 90 % covered by appressed simple golden hairs 0.1–0.2 mm long; androphore 5 winged, drying black, 2 mm long, glabrous or with 1–2 hairs; anther head subglobose, c. 1 by 1.1 mm, white; anthers 6, one apical, the remainder uniseriate. Female inflorescence as the male 12–16 by 2.8–4.5 cm, peduncle 4–6 by 0.15–0.2 cm, partial-peduncles (3–) 4–5.5 mm long, 30–58, proximal half 2–3-flowered, distal half 1–2-flowered; pedicels 3–5 mm long; tepals oblong 3 by 1.5 mm; ovary narrowly ovoid 4–5 by 1.5 mm, stigmas 3–4, bilobed, apices rounded. Infructescence 16–26 by 5 cm, peduncle 8–11 by 0.25 cm; fruits fusiform 1.5 by 0.3–0.4 cm. Seeds filiform, 0.5 by 0.025 mm, pale yellow, central body dentate.

Distribution & Ecology — Only known currently from the area of the Weda Bay Nickel Project in Halmahera, North Maluku, Indonesia. Open areas in lowland (rarely lower montane) forest on ultramafic substrate; 10–500(–760) m altitude.

Vernacular name — Woégò (Sawai language, fide De Haan 1718).

Additional specimens examined. INDONESIA, North Maluku Province, Central Halmahera, Weda Bay , sterile, lower pitcher, 27 Jan. 2013, Mahroji & Gushilman 211 ( BO n.v., MO); Bukit Limber, fr., 2 Oct. 2012, Phillipson et al. 6450 ( BO n.v., MO); ibid., Kao Rahai, female infl., 6 Dec. 2012, Bangun et al. 267 ( BO n.v., MO); ibid., Kao Rahai, male infl., 8 Dec. 2012, Bangun et al. 332 ( BO n.v., MO); ibid., Kao Rahai, female infl., 10 Mar. 2012, Bangun et al. 637 ( BO n.v., MO 2 sheets); ibid., Casuarina, male infl., 24 Mar. 2013, Bidault et al. 1154 ( BO n.v., MO 2 sheets); ibid., Sake West, buds, 18 June 2013, Bangun et al. 812 ( BO, MO) ; ibid., Kao Rahai , seedling, 27 Apr. 2013, Hidayat et al. 5086 ( BO n.v., MO) .

Conservation — Although it is possible, even probable, that N. halmahera occurs outside the footprint of the Weda Bay Nickel Project in Halmahera, there is as yet no evidence of this. Many species of ultramafic habitats are point endemics ( Ashton 2014). Therefore, using the precautionary principle, this species is here assessed as Critically Endangered B2ab(iii) according to the Categories and Criterion of IUCN (2012). This is because although seven sites and at least that number of mature individuals are known for N. halmahera , resulting in an ‘area of occupancy’ (as defined in IUCN 2012) of 32 km 2 using the preferred IUCN standard of 4 km 2 grid cells, they all appear to be within a single ‘threat-based’ location in the sense of IUCN (2012). That is to say that all currently known individuals of this species, since they are on the WBNP concession, are considered likely be at risk of extinction within the next 10– 20 years due to the ground clearance that will be needed to put in place the infrastructure (roads, processing areas, port, accom- modation, storage areas, waste areas) and open-cast mining pits planned imminently by the Weda Bay Nickel Project as expounded in ERM (2010). However, while the concession area is in the order of 50 000 ha, only c. 10 % is expected to be cleared due to the direct impact (the ‘footprint’) of the intended mine. The project intends to adopt the Mitigation Hierarchy (BBOP 2015), seeking options both to avoid and/or minimise, and if necessary to implement restoration trials, and offsetting residual losses, for species that have been assessed as of conservation significance (G. Lee pers. comm. to M. Cheek, June 2012). Given the facts expressed above, and the relatively widespread distribution of N. halmahera within the survey area, there is every chance that this species might survive in the wild if the project commitment to conservation continues at its current level.

Notes — The label data for almost all of the specimens of this species refer to it being found specifically in the more open areas of its lowland forest on ultramafic substrate habitat. This is not a spectacular species in comparison to N. weda . The pitchers are relatively small and green. This is reflected on the Tropicos website, since, while all of the six specimens known of N. weda have accompanying photographs taken in the field, for N. halmahera , this is true for only two of the eleven specimens. The type was considered an aberrant specimen of N. danseri by Jebb & Cheek (1997).

The earliest known locality in Weda District, ‘Nucifera’, has not been traced, it probably refers to a coconut plantation.

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Figures

Fig. 1 Nepenthes halmahera Cheek. a. Habit, climbing stem with upper pitchers and female inflorescences; b. leaf margin from a, showing sparse hairs; c, d. lower pitchers; e. indumentum of upper pitcher, mid-lateral area; f. peristome, upper pitcher, from above (left), and from inside (right); g. peristome, upper pitcher, transverse section, inside to right; h. spurs from upper pitchers showing the forked and glabrous distal positions; j. partial-inflorescence, female (detail from a); j. indumentum from lower pitcher, mid-lateral area; k. peristome from lower pitcher, viewed from above (left) and from inside (right); l. peristome, lower pitcher, transverse section, inside to right; m. fringed wing of lower pitcher; n. lower surface of lid, lower pitcher; o. nectar glands from n, proximal area at midline; p. partial-inflorescence, male; q. male flower showing minute sparse nectar glands in proximal third of tepal areas (a, b, e–i, p, q from Bangun et al. 332; c, d, j–o from Mahroji et al. 211). — Scale bars: a, c, d = 5 cm; b, e–g, j–l = 1 mm; h, m, o, q = 2 mm; i, p = 5 mm; n = 1 cm. — Drawn by Andrew Brown.