Nepenthes dubia

Synonymy

Nepenthes dubia Danser in Bull. Jard. Bot. Buitenzorg, sér. 3, 9: 285, f. 4. 1928 sec. Cheek & Jebb 2001

Isotype: Indonesia, Sumatra, Mt Talamaku (Ophir), alt. 1900 m, 29 May 1917, Bünnemeijer 938 (BO)
Lectotype (designated by Jebb, M. H. P. & Cheek, M. R. 1997: 361): Indonesia, Sumatra, Mt Talamaku (Ophir), alt. 1900 m, 29 May 1917, Bünnemeijer 938 (BO)

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

=? Nepenthes tenuis Nerz & Wistuba in Carniv. Pl. Newslett. 23(4): 104, f. 2. 1995 syn. sec. Cheek & Jebb 2001

Holotype (designated by Nerz, J. & Wistuba, A. 19952): Sumatra, Taram, river Tjampo, alt. 1000 m, 24 Aug 1957, Meijer 6949 (L)

2. Nerz, J. & Wistuba, A. 1995: Five new taxa of Nepenthes (Nepenthaceae) from North and West Sumatra. – Carniv. Pl. Newslett. 23(4): 101-114

– "Nepenthes bongso" sensu Tamin & Hotta 1986: 834, non Korth., p.p., err. sec. Cheek & Jebb 20013

3. Cheek, M. R. & Jebb, M. H. P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15. – Leiden: Nationaal Herbarium Nederland, Universiteit Leiden branch, 4. Tamin, R. & Hotta, M. 1986 – In: Hotta, M., Diversity and Dynamics of Plant Life in Sumatra. – Kyoto: Sumatra Nature Study (Botany), Kyoto University

Content

Other sources

Jebb, M. H. P. & Cheek, M. R. 1997: A skeletal revision of Nepenthes. – Blumea 42(1): 1-106: 36

Description

Epiphytic climber to at least 0.8 m tall. Stem terete, 3-4 mm diam., internodes of climbing stems 2.5-4 cm long. Leaves coriaceous, sessile, rosette and short stem leaves unknown, leaves of climbing stems narrowly oblanceolate-elliptic, 5.9-8 by 1.1-1.9 cm, apex acute, base clasping the stem for 1/2 its circumference, not decurrent or auriculate. Longitudinal nerves 2 on each side of the midrib near the margin, inconspicuous. Pennate nerves numerous, held at 45° from the midrib, not reaching the longitudinal veins. Lower pitchers unknown. Upper pitchers infundibulate, 4.5-5.5 cm tall, the lower half narrowly subcylindrical, 1-1.1 cm wide, the upper half abruptly broadly in-fundibulate, 2.6-3 cm wide, fringed wings absent, ridges inconspicuous; mouth orbicular to broadly elliptic, horizontal, straight; peristome flattened, 3-4 mm wide, with fine raised ribs 0.25-0.5 mm apart, outer margin slightly sinuate, inner edge lacking teeth; lid very narrowly oblanceolate-elliptic, flat, 2.7-3.2 by 0.35-0.5 cm, apex rounded, base cuneate, lower surface lacking appendages, nectar glands fairly dense, orbicular, bordered, 0.15 mm diam., along the midline elliptic, c. 0.2 mm long; spur simple, recurved, 3-5 mm long. Male inflorescence unknown. Fruit unknown. Seed unknown. Indumentum lacking on stem apart from axils with short, simple white and brown hairs. Pitchers sometimes with a very few short white hairs. Blackish hairs present at the base of the lid. Colour of pitchers yellowish green.A

Notes

2. Nepenthes dubia is possibly a hybrid between N. inermis and N. bongso (Danser in Bull. Jard. Bot. Buitenzorg III 9 (1928) 286). Nepenthes tenuis is included here with some hesitation, the pitcher being somewhat broader in its lower half and the altitude (1000 m) being considerably lower than in the remaining collections, but in other respects it matches N. dubia.B

1. Prior to Danser’s work in Bull. Jard. Bot. Buitenzorg III 9 (1928), Backer had intended to name this species ‘linguifer’, and proposed to include it with specimens of N. inermis. Nepenthes inermis shares a similar shaped pitcher, lid and leaf blade shape. The differences are that N. dubia has fewer longitudinal nerves, a slightly broader and reflexed lid (5 mm vs. 3 mm) with more numerous, but much smaller glands, and bears a peristome, which N. inermis completely lacks. Nepenthes dubia was reduced to N. bongso, along with N. inermis by Tamin & Hotta in Diversity and Dynamics of Plant Life in Sumatra (1986).C

Distribution (General)

C Sumatra.A

Bibliography

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

B. Danser, B. H. 1928: – Bull. Jard. Bot. Buitenzorg, sér. 3, 9: 286

C. Danser, B. H. 1928: – Bull. Jard. Bot. Buitenzorg, sér. 3, 9

Specimens

Country	Date	Collector + collecting number	Herbaria
Indonesia	1917-05-29	Bünnemeijer 938	BO(2)
Citation: Indonesia, Sumatra, Mt Talamaku (Ophir), alt. 1900 m, 29 May 1917, Bünnemeijer 938 Specimen summary: BO Lectotype of Nepenthes dubia Danser
	1957-08-24	Meijer 6949	L
Citation: Sumatra, Taram, river Tjampo, alt. 1000 m, 24 Aug 1957, Meijer 6949 Specimen summary: L Holotype of Nepenthes tenuis Nerz & Wistuba