Nepenthes diatas

Nepenthes diatas

Synonymy

Nepenthes diatas Jebb & Cheek in Blumea 42(1): 33, f. 4. 1997 sec. Cheek & Jebb 2001
    • Isotype: Sumatra, Aceh Province, G. Bandahara, 10 km NE of Seldok, 25 km N of Kutacane, De Wilde & De Wilde-Duyfjes 14927 (K).
    • Holotype: Sumatra, Aceh Province, G. Bandahara, 10 km NE of Seldok, 25 km N of Kutacane, De Wilde & De Wilde-Duyfjes 14927 (L).

Description

Terrestrial subscandent shrub to 2.5 m tall. Stem base woody; stem quadrangular, angles being most marked below the nodes, 0.4-0.8 cm diam., internodes 1-3.5 cm long. Leaves thinly coriaceous, sessile, leaves of climbing stems oblanceolate, 9.5-17 by 2.5-3.5 cm, apex acute, base attenuate, subparallel-sided, to 1.6 cm wide, clasping the stem for 1/2 its circumference, occasionally auriculate. Longitudinal nerves 3 or 4 on each side of the midrib, in outer half of blade, fairly conspicuous. Pennate nerves numerous, oblique and parallel, inconspicuous. Lower pitchers not known. Upper pitchers ventricose in lower 1/3, cylindrical to slightly infundibuliform in upper 2/3, and gradually broadening towards mouth, 14-22 by 3-4.5 cm; with prominent ridges, and rarely with very short fringed wings immediately below peristome to 1 cm broad including fringed elements; mouth oblique and slightly concave; peristome woody, 5-15 mm wide, rounded at front, flattened towards lid, ribs 1-2.5 mm apart, to 1.5 mm high, outer edge entire and extending further than inner edge, inner edge toothed, teeth to 2.5 mm long; lid orbicular, 3.2-6.5 cm diam., apex rounded to truncate, base cordate, lower surface lacking appendages, thickened on midline, nectar glands circular, 0.15 mm diam., very numerous, on midline larger, elliptic, to 0.6 mm long; spur simple to 12 mm long. Male inflorescence 26-38 cm long, flowers clustered and dense in topmost 1/3-1/4; partial peduncles 1-flowered, rarely 2-flowered, 5-10 mm long; bract c. 6 mm long, flattened, inserted at the base of the partial peduncle, or even somewhat below on the rhachis; tepals ovate, 4-6 by 2-3 mm; androphore 2-4 mm long; anther head 2 by 2.5 mm. Fruit valves 27-32 by 3-4 mm. Seeds unknown. Indumentum of erect reddish brown hairs c. 0.5 mm long, more or less dense throughout, absent from upper leaf blade, soon glabrescent, but persistent on tendril and in leaf axils, and dense on inflorescence, including staminal column and valve. Colour of pitchers reddish brown; flowers brownish or purple-brown, or tepals rusty, purple inside; anthers pale yellow; fruits rusty brown.A

Notes

Nepenthes diatas is part of the Sumatran N. singalana group. In its ventricose-tubular upper pitchers and attenuate, subparallel-sided leaf bases it resembles N. singalana and N. spathulata, but differs from both in the woody, rather than papery, peristome. It is probably derived from N. singalana, representing a far more robust version of that species.
Collections of lower and rosette pitchers are needed to complete our knowledge of N. diatas.A

Distribution (General)

N Sumatra.A

Etymology

Diatas is a Bahasa Indonesian word for ‘on top’: the species is found both on top of mountains, and in Aceh, the most northerly, or ‘topmost’ region of Indonesia.A

Habitat

Montane scrub and mossy forest; 2400-2600 m.A

Bibliography

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

Images

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
De Wilde & De Wilde-Duyfjes 14927K, L
Citation: Sumatra, Aceh Province, G. Bandahara, 10 km NE of Seldok, 25 km N of Kutacane, De Wilde & De Wilde-Duyfjes 14927.

Specimen summary: K
Isotype of Nepenthes diatas Jebb & Cheek

Specimen summary: L
Holotype of Nepenthes diatas Jebb & Cheek