Nepenthes sibuyanensis

Nepenthes sibuyanensis

Synonymy

Nepenthes sibuyanensis Nerz in Carniv. Pl. Newslett. 27(1): 18 (-23, fig. 1, 2, frontisp.). 1998 sec. Cheek & Jebb 2001
    • Holotype: Philippines, Sibuyan, Mt Guintguintin (Guiting-Guiting), alt. 1300 m, 5 Oct 1996, P. Mann & T. Smith 051001 (L).

Description

Terrestrial shrub or climber 0.7-2 m tall. Stems terete or 3- or 4-angled, 0.8-0.9 cm diam., internodes 1-5 cm long in climbing stem. Leaves thinly to thickly coriaceous, sessile, linear-lanceolate, linear-oblong or slightly spathulate, 10-21 by 2.4-3.8(-5) cm, apex acute to rounded, often slightly peltate, base gradually or barely attenuate to the stem, decurrent as narrow wings 2-3 mm wide for 2/3, to a whole internode and converging towards the opposite surface of the stem. Longitudinal nerves 5 or 6 on each side of the midrib, in the outer 1/2-2/3 of the blade. Pennate nerves not conspicuous. Lower and upper pitchers apparently similar, shortly ovoid-cylindrical, to 20(-25) by 12(-15) cm, fringed wings 2-3 mm wide in the upper 2/3 of the lower pitchers on-ly, absent in the upper pitchers; mouth ovate to suborbicular, horizontal to slightly oblique, abruptly rising at the rear into a short, broad neck c. 2 by 2 cm; peristome slightly rounded, 20-30 mm broad, the ribs 1 mm high, 2 mm apart, outer margin undulate, with 6-8 shallow lobes; inner margin recurved, bearing teeth 3-4(-5) mm long and up to 5 times as long as broad; lid held over and parallel with mouth, ovate, 8-10.5 by 6.5-7.1 cm, apex rounded or obtuse, base shallowly cordate; lower surface lacking appendages, glands few, absent from the midline, the central area and the marginal area, 35-60 in total, sparsely scattered, pit-like, transversely elliptic, 0.8-2.1 mm long; spur filiform, 2-3 by 0.5 mm. Male inflorescence c. 32 cm long, c. 3 cm at the widest point; peduncle 18 cm long, 0.6 cm diam. at the base; partial peduncles 1-flowered; bracts highly reduced; pedicels 12-14 mm long at the base of the inflorescence; tepals oblong, 3 mm long, obtuse; androphore c. 5 mm long. Fruit 18-22 by 3-4 mm. Seeds filiform, 8 mm long. Indumentum of sessile red glands 0.1 mm present only on the densely appressed stellate-hairy inflorescence; androphore puberulent. Colour of pitchers green or yellowish to dull orange or pink with a few red blotches 5-10 mm diam. in the upper third; peristome bright glossy red to purplish black; lid yellowish orange or pale green suffused with pink above.A

Notes

Nepenthes sibuyanensis is closely similar and seems very closely related to N. ventricosa, a species fairly widespread in Luzon, and to N. burkei, endemic to Mindoro. The differences are given in the key, the most conspicuous being the larger pitchers which lack any sign of constriction at the midpoint. These three species form part of the Insignes group.
The above description is taken partly from the protologue, in which the description of the upper and lower pitchers are united. Figures given in brackets in the description are taken from dimensions given by the collector of the type in a detailed article on the discovery of this species (Mann Carnivorous Plant Newsl. 27 (1998) 6). Apparently nearly sympatric with N. argentii, from which it is inferred that the shrubby grassland habitat of N. sibuyanensis is also induced by ultramafic soils. Known only from five collections (P. Mann & T. Smith 015001-015004, L n.v.) collected at the type locality on 5 October 1996 and Argent & Reynoso 89128 (E n.v., K, PNH n.v.).A

Distribution (General)

Philippines: Sibuyan Island.A

Habitat

Open grassy slopes among Dipteris conjugata and high grasses with small shrubs, probably on ultramafic soils, 1350-1800 m. Flowering: Oct. 1996.A

Bibliography

A. Cheek, M.R. & Jebb, M.H.P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15

Images

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
1996-10-05P. Mann & Smith, T. 051001L
Citation: Philippines, Sibuyan, Mt Guintguintin (Guiting-Guiting), alt. 1300 m, 5 Oct 1996, P. Mann & T. Smith 051001.

Specimen summary: L
Holotype of Nepenthes sibuyanensis Nerz