Nepenthes tobaica

Synonymy

Nepenthes tobaica Danser in Bull. Jard. Bot. Buitenzorg, sér. 3, 9: 382, f. 23. 1928 sec. Cheek & Jebb 2001

Lectotype: Sumatra, Habinsaran plateau, ESE of Lake Toba, alt. 1200 – 1300 m, 11 May 1919, Lörzing 6573 (BO)
Isotype: Sumatra, Habinsaran plateau, ESE of Lake Toba, alt. 1200 – 1300 m, 11 May 1919, Lörzing 6573 (BO)
Isotype: Sumatra, Habinsaran plateau, ESE of Lake Toba, alt. 1200 – 1300 m, 11 May 1919, Lörzing 6573 (L)

Content

Other sources

Tamin, R. & Hotta, M. 1986 – In: Hotta, M., Diversity and Dynamics of Plant Life in Sumatra. – Kyoto: Sumatra Nature Study (Botany), Kyoto University: 107

Kurata, S. 1973: – Gard. Bull. Singapore 26(2): 232

Jebb, M. H. P. & Cheek, M. R. 1997: A skeletal revision of Nepenthes. – Blumea 42(1): 1-106: 86

Description

Terrestrial climber to 5 m tall. Stem ± terete or rounded-triangular, 0.15-0.4 cm diam., usually zigzagging slightly, with prominent axillary buds 0.5-1 mm long, basal rosettes unknown. Leaves coriaceous, sessile, often reflexed; leaves of climbing stems narrowly elliptic or oblanceolate (4-)5.5-14 by 0.7-1.9 cm, apex acute, the basal third often distinctly constricted, c. 3.5 mm wide, clasping the stem for 2/3 its circumference, very shortly and obliquely decurrent, and slightly auriculate, the auricles reflexed. Longitudinal and pennate nerves inconspicuous. Lower pitchers very rarely collected, ± ellipsoid in the lower half, gradually tapering to the cylindrical upper half, c. 8.5 cm long, 2.7 cm wide at the base, 2.1 cm wide at the apex, with 2 fringed wings to c. 5 mm broad, the fringed elements to 0.4 cm; mouth ± ovate, oblique, peristome cylindrical, 0.5-0.75(-1.2) mm wide, with fine, raised ribs, outer edge entire, inner without teeth; lid broadly elliptic, c. 1.9 by 1.7 cm, apex rounded, base slightly cordate to truncate, lower surface lacking appendages, nectar glands numerous, dense over whole surface, minute, volcano-like or thickly bordered, 0.1-0.15 mm diam.; spur simple, unbranched, to 4 mm long. Upper pitchers as lower pitchers but very slightly ventricose, (4.5-)6-9.7(-13) cm long, 1.3-2.2 cm wide at the base, narrowing slightly to (0.5-)1.2-2.1 cm wide at the waist and expanding to (7.5-)1.5-2.5 cm at the mouth, with two ridges to c. 0.1 cm broad, lacking fringed elements. Male inflorescence 15-30 cm long; peduncle 7-14 cm long; partial peduncles 2-flowered, 4.5-6.4 mm long; bracts rarely present; pedicels 5.5-11 mm long; tepals 3-3.5 by 2-2.5 mm; androphore 2-2.5 mm; anther head 1 by 1-1.25 mm. Fruit with valves 16-35 mm long. Seeds fusiform, minutely tuberculate in the centre. Indumentum absent from the stems apart from distinct tufts of white hairs in the leaf axils; leaves glabrous when expanded, slightly hairy in bud; inflorescence with appressed stiff white hairs often sparse, extending to the androphore; ovary with sparse coppery hairs. Colour of stems light green to dark brown; pitchers light green or yellowish green with red parts; rarely wholly red or green; staminal column light green.A

Notes

Nepenthes tobaica was long confused with N. mikei. The last can be distinguished by its fasciculate or branched pitcher spurs, its broader peristome (2.5 mm vs. 0.5-1 mm wide) and its shorter inflorescence (7-15 cm vs. 15-35 cm) with 1-flowered, not 2-flowered, partial peduncles. Nepenthes tobaica is sometimes also confused with N. reinwardtiana but can be distinguished by the absence of pitcher ‘eye-spots’, the presence of tufts of white hairs in the leaf axils, and the rounded stem with non-decurrent leaf bases.
Of the three duplicates of Lörzing 6573, the sheet with both male and female inflorescences is the lectotype. The Lörzing number ‘6802’ in Danser in Bull. Jard. Bot. Buitenzorg III, 9 (1928) 384is an error for 8602, as shown in the caption to f. 23 (1928).A

Distribution (General)

Sumatra: Lake Toba to G. LeuserA

Habitat

Montane forest edges, amongst Leptospermum/Rhodomyrtus and in the scrub of old clearings; 950-2750 m.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

Specimens

	Country	Date	Collector + collecting number	Herbaria	Type	Scan	Derivatives
		1919-05-11	Lörzing 6573	BO(2), L
	Citation: Sumatra, Habinsaran plateau, ESE of Lake Toba, alt. 1200 – 1300 m, 11 May 1919, Lörzing 6573 Specimen summary: BO Lectotype of Nepenthes tobaica Danser Specimen summary: L Isotype of Nepenthes tobaica Danser