Nepenthes hamata

Nepenthes hamata


Nepenthes hamata J.R.Turnbull & A.T.Middleton [as "hamatus"] in Reinwardtia 10(2): 108. 10 Feb 1984 sec. Cheek & Jebb 2001 wfo-0001302559
      C Sulawesi, G. Lumut W ridge, alt. 1850 – 1900 m, 19 Sep 1983, J.R. Turnbull & A.T. Middleton 83121a. (BO)
  • =Nepenthes dentata Sh.Kurata in Gard. Bull. Singapore 36(2): 197 (-200, pl. 1, f. 1). 1984 syn. sec. Cheek & Jebb 2001 wfo-0000381956
  • Nepenthes dentata Sh.Kurata, Nepenthes of Mt Kinabalu, Sabah: 11. 1976, nom. nud. syn. sec. Cheek & Jebb 2001 wfo-0001302688
    • Lectotype: C Sulawesi, G. Lumut, between bivouac II and III on N spur, 3 Sep 1938, Eyma 3572 (BO; isotype: BO)

Other sources

Nepenthes hamata J.R.Turnbull & A.T.Middleton: Jebb, M. H. P. & Cheek, M. R. 1997: A skeletal revision of Nepenthes. – Blumea 42(1): 1-106. p 46 (as Nepenthes hamata J.R.Turnbull & A.T.Middleton)
Nepenthes dentata Sh.Kurata: Kurata, S.: – Gard. Bull. Singapore 36. 197, f. 1, t. 1 (as Nepenthes dentata Sh.Kurata)


Terrestrial climber to several metres high. Stem terete or obtusely trigonous, climbing stem 4-5 mm diam., internode length 3.5-6 cm, stems of short stems and rosettes 2-3 mm diam., internodes 2-6 mm long. Leaves chartaceous, sessile, those of short stems and rosettes oblanceolate or oblong-elliptic, 6-7.5 by 1.7-2.5 cm, apex acute, not peltate, base amplexicaul, subperfoliate, more or less auriculate, not conspicuously decurrent; leaves of climbing stems oblong-elliptic, rarely lanceolate, 5-7(-15) by 1.8-2.5 cm, apex obtuse to acute, base decurrent by 0.5-1.5 cm. Longitudinal nerves 2(-4) on each side of the midrib, in the outer 1/2-1/3(-2/3). Pennate nerves patent, branching, inconspicuous. Lower pitchers narrowly ovoid, 7-11.5 cm tall, 2.1-3.2 cm wide at the base, diminishing gradually to 1.6-2.5 cm wide below the mouth; fringed wings 3 mm wide, fringe elements often in pairs, 2 mm apart, 5-10 mm long, branching dichotomously 1 or 2 times; mouth concave, highly oblique, elliptic, with a long tapered apex that becomes erect, or overarches the rest of the mouth; peristome cylindrical to slightly flattened, 1.5-3 mm wide (excluding teeth), ribs c. 3 mm apart, c. 20 on each side, exaggerated into falcate teeth c. 5 mm high, outer edge entire, teeth recurved, c. 2 mm from peristome to apex, inner edge recurved into the pitcher, c. 7 mm from pitcher rim to the tooth apex, teeth of column dagger-like, descending 10 by 2 mm; lid held horizontally, margins ascending, ovate, 3-3.8 by 1.8-2.8 cm, apex rounded, base subcordate, upper surface with up to 45 multicellular ‘tentacles’ on each side, c. 3 deep around the margin, each 6-8 mm long, often branched, arising from vein ends, lower surface lacking appendages, with sparse and inconspicuous shortly elliptic bordered pits 0.1-0.2 mm broad; spur fasciculate, 5-branched from the base, c. 9 mm long, each repeatedly branched along its length. Upper pitchers subcylindrical, usually slightly ovoid in the lower 1/3, the upper 2/3 cylindrical, or gradually dilating slightly towards the mouth, 7-20 by (1.2-)2-4.5 cm, with fringed wings or with the wings reduced to ridges; peristome with teeth 12-16 by 2-3 mm high, 2.5-6 mm apart. Male inflorescence 8-15 cm long; peduncle 2.4-10 cm long; partial peduncles 1-flowered, c. 22; bracts absent; pedicels 10-15 by 0.1-0.3 mm; tepals elliptic, reflexed, 1.5-2.5 by 1-1.5 mm; androphore 1-2.5 mm long; anther head 0.6-0.8 by 0.8-1.4 mm. Infructescence 8.5 by c. 5 cm; peduncle 6.5 cm long, 2.25 mm diam. at base. Fruits c. 15; valves 19-20 by 3.5-4.5 mm. Seeds filiform, 8 by 0.4-0.6 mm. Indumentum of sessile red glands on stem, lower surface of leaves, outer surface of pitchers, upper and lower lid; outer pitcher arachnoid-tomentose with branched brown, often prostrate and crinkled hairs 0.3-1.5 mm long; inflorescence from peduncle to lower surface of tepals sparsely to moderately densely covered with appressed brown hairs c. 0.5 mm long; ovary densely hairy with golden-brown appressed hairs. Colour of pitchers pale green blotched/reticulated purplish red with mauve wings; peristome red or black, teeth black or greenish white; male flowers green, tepals becoming red.A


This species is related to N. tentaculata. Amongst the most notable similarities are the presence of hair-like appendages (‘tentacles’) on the lid, the branched spur surrounded by other branching appendages, the lids of the lower pitchers often lacking glands, and the upper pitchers which may or may not bear fringed wings. The features which distinguish this species are the striking peristome, with plate-like teeth, but this only develops in the upper pitchers and is variable in the degree of development. It appears that the N. tentaculata group of species (N. adnata, N. glabrata, N. hamata, N. muluensis, and N. tentaculata) are all similar in their lower pitchers and leaves, in particular the presence of tentacles on the upper surface of the lid. Some specimens of N. hamata appear to be very close to N. tentaculata, and at present the seven or so collections available form something of a continuum. Kurata’s description and selected type represent an extreme form (as illustrated in his figure). The material selected by Turnbull & Middleton has not been located, but the description suggests it is somewhat of an intermediate between Kurata’s material of N. hamata and N. tentaculata. Rather than intermediates between species, however, this variation is more likely to be explained by the dimorphy of lower and upper pitchers. A similar case holds with N. muluensis, where the lower pitchers have only recently been discovered to show the typical facies of N. tentaculata (see there).
This species was first mentioned in a list by Kurata (Nepenthes of Kinabalu, Sabah (1976) 10) as N. dentata nom. nud., validated in a paper eight years later (Kurata, Gard. Bull. Sing. 36 (1984) 197). A few days before N. dentata was validated, however, the description of N. hamata appeared in a preprinting of Reinwardtia, with an effective publication date of 10 February 1984, gaining priority by 28 days. The effective publication date of these two names is open to debate. Whether the ‘preprinting’ fulfilled the condition of being ‘freely available (Art. 29)’ before the Kurata paper is hard to determine. It was certainly not deposited at libraries at either K or E prior to the accession of volume 36 of the Gardens’ Bulletin of Singapore which arrived at both libraries in June 1984. The Reinwardtia volume arrived in August 1985 (K) and November 1985 (E). Turnbull & Middleton published (Reinwardtia 10, 2 (1984)) three species names from their Sulawesi collections: N. hamata, N. glabrata, and N. infundibuliformis. None of these collections has been found at the herbaria they cite.A
Belongs to Nepenthes sect. Tentaculatae Cheek & JebbB

Distribution (General)

Sulawesi: C Province (G. Lumut, G. Sojol, Mt Tambusisi, Mt Roroda Timbu, Tomongkobae Mts&G. Poka Pindjang).A


On open ridge-tops, rooted in moss, climbing into trees; 1400-2500 m.A


A. Cheek, M. R. & Jebb, M. H. P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15. – Leiden: Nationaal Herbarium Nederland, Universiteit Leiden branch
B. Cheek, M. R. & Jebb, M. H. P. 2016: A new section in Nepenthes (Nepenthaceae) and a new species from Sulawesi. – Blumea 61: 59-62



CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
3 Sep 1938Eyma 3572BO
Citation: C Sulawesi, G. Lumut, between bivouac II and III on N spur, 3 Sep 1938, Eyma 3572

Specimen summary: BO
Lectotype of Nepenthes dentata Sh.Kurata

19 Sep 1983Turnbull, J. R. & Middleton, A.T. 83121a.BO
Citation: C Sulawesi, G. Lumut W ridge, alt. 1850 – 1900 m, 19 Sep 1983, J.R. Turnbull & A.T. Middleton 83121a.

Specimen summary: BO
Type for: Nepenthes hamata J.R.Turnbull & A.T.Middleton