Nepenthes jamban

Nepenthes jamban


Nepenthes jamban Chi.C.Lee, Hernawati & Akhriadi in Blumea 51(3): 563 (-565; fig. 1). 2006 [The specific name refers to the word ‘jamban’ in Indonesian, due to the resemblance of the pitcher shape to a toilet receptacle.B]. sec. Lee & al. 2006 wfo-0000507679
      Type: Lee, Hernawati, Akhriadi NP 433 (ANDA), Indonesia, Sumatera Utara, Bukit Barisan, south of Padang Sidempuan, 22 April 2005.


Terrestrial climber to c. 4 m tall. Stems of rosettes and short shoots cylindrical-angular, c. 3 mm diam., internodes 1–1.3 cm long. Climbing stems to 0.5 cm diam., internodes 1.8 – 5 cm long. Leaves of rosettes coriaceous, sessile, narrowly obovate to elliptic or slightly spathulate, apex acute, 9 –10.3 by 2.2 – 3 cm, clasping stem for 3/4 circumference; longitudinal veins 1 or 2 on each side of the midrib, located in the outer 1/4 of the lamina, pinnate veins arising obliquely from the midrib; tendrils straight, to 13 cm long. Leaves of climbing stems as those of rosettes, but lamina ovate to elliptic to slightly spathulate, usually contracted into a parallel-sided basal section, 7–11 by 2.6 – 3.3 cm, base clasping the stem for 1/2 – 2/3 of its circumference and not decurrent; tendrils with a curl in the middle, 15 – 24 cm long. Lower pitchers originating laterally from the tendril, 3.5 – 5.8 by 3.2 – 4.4 cm, cylindrical to narrowly infundibular in the lower third, rapidly becoming widely infundibular above, somewhat compressed laterally, not hipped, mouth almost horizontal; inner surface glandular throughout; wings usually present on the front of the pitcher, to 10 by 2 mm wide with fringe elements c. 3 mm long; peristome flattened, to 0.8 cm wide, joined to the pitcher in the outer third, the inner side slightly incurved; ribs c. 0.7 mm apart at front, closer and less pronounced towards lid; inner margin ending in teeth c. 0.5 mm long; spur usually simple, sometimes forked, inserted at base of lid, c. 4 mm long; lid narrowly obovate, 3.5 – 3.8 by 0.9 –1.3 cm, held horizontally over the mouth, with sides folded upwards at c. 120°, undersurface with scattered small red glands concentrated around the midrib and a few (c. 20 – 30) very large crater-like glands, c. 0.5 mm diam., present in the apical 1/4, which are visible on the upper surface of the lid as distinct swellings. Upper pitchers originating from the tendril at the rear of the pitcher, 7.5(–12) by 5.2 cm, expanding very gradually in the lower half and abruptly becoming widely infundibular in the upper half, circular in cross section, not hipped, mouth horizontal and orbicular; inner surface glandular throughout; wings absent but present in lower half of pitcher as reduced ribs; peristome flattened, to 0.6 cm wide, joined to the pitcher in the outer third, ribs c. 1 mm apart and 0.5 mm tall; inner margin ending in teeth c. 1 mm long; spur usually simple, inserted at base of lid, to 3.5 mm long; lid as in lower pitchers but longer, to 4.8 by 0.9 cm, held over the mouth at an angle of c. 45°. Male inflorescence a raceme, 18 by 2 cm; peduncle to 4.2 – 6.5 cm long, rachis 8.2 –11.5 cm, pedicels 0.5 –1.4 cm long, each bearing a single flower, with a filiform bract 2 – 9 mm long inserted c. 1 mm from the base of the pedicel; sepals elliptical, c. 3.5 mm long; staminal column 1.5 – 3 mm long. Female inflorescence unknown. Ripe infructescence a raceme, peduncle 5 cm long, rachis 3 cm long, pedicels to 1.4 cm long, each bearing a single fruit, with a filiform bract c. 4 mm long inserted c. 2 mm from the base of the pedicel; fruit to 3 by 0.6 cm; seeds filiform, c. 2 cm long. Indumentum: all parts of the plant glabrous except for developing pitchers, tendrils, and inflorescence which are densely covered with short brownish grey hairs. Colour of living specimens: leaves light green above, pale green below, stems purplish red, inflorescence light green, lower pitchers yellowish orange to bright red with red peristome, upper pitchers bright yellow occasionally with red spots on inner surface and with yellow to orange peristome.A


This species represents another taxon in the primarily West Sumatran group which includes N. dubia, N. inermis, N. jacquelineae, and N. tenuis. With these species it shares common features including broadly infundibulate pitchers which are wholly glandular within, bracteate inflorescences, and sessile leaves. In addition, all these species have a highly viscous pitcher fluid, and it has been suggested that this may aid in the retention of insect prey, as mentioned by Clarke (2001).
The upper pitchers of N. jamban have been regularly observed to be filled with numerous large insect prey items including wasps and crickets and with very few small prey such as ants. Most upper pitchers also support large populations of living mosquito larvae.
Nepenthes jamban appears most closely related to N. jacquelineae with which it shares a similar growth habit and pitcher structure. Both of these species possess unusually large nectar glands on the undersurface of the pitcher lid which are so robust that they produce small bumps on the lid’s upper surface. However, N. jacquelineae differs in having a more robust habit, a widely expanded smooth peristome, shorter and 2-flowered partial peduncles, and a wider pitcher lid.
At the type locality (currently the only known locality for this species), N. jamban is sympatric with N. bongso, N. dubia, N. gymnamphora, and N. lingulata, though no natural hybrids have been observed. The fact that the closely related N. dubia occurs in the same habitat with no apparent introgression is worthy of note as this is the first record of two sympatric taxa in this species group.A

Distribution (General)

Indonesia, Sumatra (Sumatera Utara, Bukit Barisan)A


Upper montane mossy forest and summit scrub vegetation, growing terrestrially.A


A. Lee, C.C., Hernawati & Akhriadi, P. 2006: Two new species of Nepenthes (Nepenthaceae) from North Sumatra. – Blumea 51(3): 561-568


CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
Lee, Hernawati, Akhriadi NP 433 (ANDA), Indonesia, Sumatera Utara, Bukit Barisan, south of Padang Sidempuan, 22 April 2005.
Citation: Lee, Hernawati, Akhriadi NP 433 (ANDA), Indonesia, Sumatera Utara, Bukit Barisan, south of Padang Sidempuan, 22 April 2005.