Nepenthes rhombicaulis

Nepenthes rhombicaulis


Nepenthes rhombicaulis Sh.Kurata in Gard. Bull. Singapore 26(2): 229, f. 1. 1973, sec. Cheek & Jebb 2001 wfo-0000381444
  • Nepenthes rhombicaulis Sh.Kurata in The Heredity 26(10): 44. 1972, nom. nud. syn. sec. Cheek & Jebb 2001 wfo-0001302624
    • Sumatra, near Prapat, G. Pangulubao, alt. 1700 – 1900 m, 29 Mar 1972, S. Kurata 4300 (Nippon Dental College, SING)

Other sources

Jebb, M. H. P. & Cheek, M. R. 1997: A skeletal revision of Nepenthes. – Blumea 42(1): 1-106. p 79


Terrestrial climber to 20 m tall. Climbing stem 4-angled, 5-10 mm diam.; short shoots and rosettes present. Leaves sessile, those of rosettes and short shoots scattered, lanceolate, several cm long; those of climbing shoots lanceolate, 12-22 by 3-4 cm, apex subpeltate to emarginate, the base clasping the stem by 1/2-2/3 its circumference, not decurrent or sheathing. Longitudinal nerves 2 or 3 on each side of the midrib in the outer 1/4 of the blade, innermost vein arising from 1/3-1/2 way along midrib. Pennate nerves oblique. Lower pitchers ventricose in the lower half, cylindrical in the upper part, 6-12 by 2.5-3.5 cm, with two fringed wings; mouth orbicular, oblique; peristome subcylindrical, 3-5 mm broad, ribs c. 0.5 mm apart, outer edge expanded and undulate, inner toothed; lid elliptic-oblong or ovate, 2.5 by 1.7-2.5 cm broad, apex rounded, base truncate, lower surface with an appendage near the apex, nectar glands bordered, c. 0.15 mm diam.; spur divided to the base with two filiform branches, c. 5 mm long. Upper pitchers unknown. Inflorescence 30-40 cm long; peduncle 15-20 cm long; partial peduncles 2-flowered, length unknown; bracts absent (not mentioned or figured in the protologue); pedicels 10-15 mm long; tepals elliptic, 4 by 3 mm; androphore 4 mm long. Fruits fusiform, valves lanceolate 20-25 by 5 mm. Indumentum of stem glabrous, with prominent glands; leaf margin reddish brown hairy; pitchers sparsely pubescent; lower surface of tepals, and fruit valves minutely pubescent. Colour of lower pitchers red or pale green with purple spots, peristome red.A


The description above is largely taken from the protologue. Nepenthes rhombicaulis is extremely poorly known although reported in the protologue as being ‘common’ on the mountains surrounding Lake Toba. Only the type collection exists. Subsequent purported field observations (Hopkins et al. Carnivorous Plant Newsl. 19 (1990) 19-28Schmid-Hollinger Carnivorous Plant Newsl. 23 (1994) 62-63 ) have not been supported by voucher specimens and their descriptions and photographs do not appear to match the type. The combination of a sharply 4-angled stem, absence of upper pitchers and presence of an apical appendage on the lower surface of the lower pitcher lid (not seen in the SING specimen) is unique: each are individually unusual characters within the genus.

Distribution (General)

N Sumatra: G. PangulubaoA


Subalpine forest; altitude unknown.A


A. Cheek, M. R. & Jebb, M. H. P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15. – Leiden: Nationaal Herbarium Nederland, Universiteit Leiden branch


CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
29 Mar 1972Kurata, S. 4300Nippon Dental College, SING
Citation: Sumatra, near Prapat, G. Pangulubao, alt. 1700 – 1900 m, 29 Mar 1972, S. Kurata 4300

Specimen summary: Nippon Dental College
Type for: Nepenthes rhombicaulis Sh.Kurata

Specimen summary: SING
Type for: Nepenthes rhombicaulis Sh.Kurata