Nepenthes hamata

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