Nepenthes hamata is a tropical pitcher plant endemic to Sulawesi, where it grows at elevations of 1,400–2,500 m above sea level.
The specific epithet hamata is derived from the Latin word hamatus, meaning "hooked". It describes the appearance of the highly developed peristome teeth of this species.
Botanical history
Early history and formal descriptions Nepenthes hamata was first encountered by Western explorers many decades before its formal description and recognition by science. Dutch botanist Pierre Joseph Eyma collected herbarium material of this species as early as 1938; this would later be used to designate a type specimen.
In 1984, two formal descriptions of this species were published in close succession: Shigeo Kurata described it under the name N. dentata in The Gardens' Bulletin Singapore, while John R. Turnbull and Anne T. Middleton called it N. hamatus in the journal Reinwardtia.
As explained in the introduction to his describing paper on N. dentata, Kurata first became aware of the species more than a decade earlier, on a 1972 visit to Herbarium Bogoriense:
The name N. dentata was first published in Kurata's 1976 guide, Nepenthes of Mount Kinabalu, where it was included in a table of all Nepenthes species known at the time and asterisked with the note "Not yet established".Kurata, S. 1976. Nepenthes of Mount Kinabalu. Sabah National Parks Publications No. 2, Sabah National Parks Trustees, Kota Kinabalu.
Questions over nomenclatural priority The formal descriptions of N. dentata by Kurata and N. hamatus by Turnbull and Middleton were published almost concurrently, leading to uncertainty over which name held nomenclatural priority. A similar situation surrounded the publication of N. eymae / N. infundibuliformis and N. glabrata / N. rubromaculata, which were described by the same three authors.D'Amato, P. 1993. Carnivorous Plant Newsletter 22(1–2): 21.
Nepenthes hamata (emended with a feminine suffix to match the gender of Nepenthes)Schlauer, J. 1994. NEPENTHES comments for Flora Malesiana. Carnivorous Plant Mailing List, September 9, 1994.Nepenthes hamata J.R.Turnbull & A.T.Middleton. International Plant Names Index (IPNI). gained greater currency and was said to have been published 21 days prior to N. dentata.Jebb, M. 1994. NEPENTHES revision for Flora Malesiana. Carnivorous Plant Mailing List, September 9, 1994. However, in 1994 Matthew Jebb wrote that the "priority of this name over N. dentata [...] is in fact in serious doubt, since the 'preprinted' Reinwardtia issue was technically not 'freely available' in terms of the Botanical Code". Taxonomist Jan Schlauer determined that the publication of Turnbull and Middleton's paper preceded Kurata's formal description of N. dentata in The Gardens' Bulletin Singapore, but came after Kurata's articleKurata, S. 1984. New species of Nepenthes from Sulawesi, Indonesia. Journal of Insectivorous Plant Society 35(2): 41–44. about the species in the Journal of Insectivorous Plant Society. While some authors referred to the species as N. dentata in the following years, Marabini, J. 1987. Eine neue Unterart von Nepenthes edwardsiana Hook.fil. sowie Anmerkungen zur Taxonomie der Gattung Nepenthes L.. Mitteilungen der Botanischen Staatssammlung München 23: 423–429. the name N. hamata enjoyed greater popularity and has for this reason been retained in all major monographs on the genus.Cheek, M.R. & M.H.P. Jebb 2001. Nepenthaceae. Flora Malesiana 15: 1–157.Jebb, M.H.P. & M.R. Cheek 1997. A skeletal revision of Nepenthes (Nepenthaceae). Blumea 42(1): 1–106.
In the years following its description, some authors considered the two taxa as separate species Marabini, J. 1988. Zur taxonomischen Klassifizierung von Nepenthes dentata Kurata und Nepenthes hamatus Turnbull et Middleton. Das Taublatt 9: 4–7. and there was even speculation among growers that N. hamata represented a hybrid involving the "true" species, N. dentata. Schlauer considers N. dentata to be a heterotypic synonym of N. hamata.
Type material The type specimen of N. hamata is J.R.Turnbull & A.T.Middleton 83121a, which was collected from the west ridge of Mount Lumut, Central Sulawesi (at the coordinates ), at an altitude of 1,850–1,900 m, on September 19, 1983.Schlauer, J. N.d. Nepenthes hamata . Carnivorous Plant Database. In their description of the species, Turnbull and Middleton indicated that the type material had been deposited at Herbarium Bogoriense (BO), the herbarium of the Bogor Botanical Gardens. However, Martin Cheek and Matthew Jebb were unable to locate it there and, referring collectively to the type material of N. hamata, N. glabrata, and N. infundibuliformis (which were all described by Turnbull and Middleton in the same paper), wrote that "[n]one of these collections has been found at the herbaria they cite".
An early collection by Dutch botanist Pierre Joseph Eyma, designated as Eyma 3572, represents the type material of N. dentata. The specimens of this series were taken from a site on the north spur of Mount Lumut, between bivouacs II and III, on September 3, 1938. Both the lectotype and isotype are deposited at Herbarium Bogoriense (BO).
In addition to the herbarium specimens of N. hamata mentioned here, a number of others have appeared in the literature.
Horticultural interest Nepenthes hamata remained very rare in cultivation until around 1996.Hansen, E. 2001. Where rocks sing, ants swim, and plants eat animals: finding members of the Nepenthes carnivorous plant family in Borneo. Discover 22(10): 60–68. Its scarcity and striking appearance made it particularly desirable to collectors, and individual plants commanded prices of approximately US$300–400 during this time. The significant commercial value of the species encouraged wild collection by both local and foreign plant hunters. Beginning in 1995, Ch'ien Lee oversaw a Nepenthes artificial propagation program at Malesiana Tropicals, a company based in Sarawak, Malaysian Borneo.Phillipps, A., A. Lamb & C.C. Lee 2008. Pitcher Plants of Borneo. Second Edition. Natural History Publications (Borneo), Kota Kinabalu. Seeds of N. hamata, which had been collected in the wild by Lee, were used to multiply plant material in vitro in the company's tissue culture laboratory. By 2001, Malesiana Tropicals had a sales inventory of more than 500 individuals of the species, supplying both hobbyists and commercial growers as well as botanical gardens and researchers. The increased supply led to a sharp fall in prices. The price of N. hamata was predicted in 2001 to stabilise at roughly $50 per plant, greatly limiting the incentive for wild collection. The species however remains highly sought-after and is still somewhat of a horticultural rarity.Heng, S.B. 2013. There's big money in pitcher plants . New Straits Times, July 13, 2013.
Discovery of "red hairy hamata"
In early 2005, Ch'ien Lee announced the discovery of a new form of N. hamata with an exceptionally dense indumentum:"Stairs" 2005. Re: New Hamata like species. CPUK Forum, June 26, 2005.
In response to subsequent speculation about the plant's taxonomic status, Lee wrote that it "merely represents a geographical variant of N. hamata". It was informally known as N. hamata "red hairy" or simply "red hairy hamata" (often abbreviated as 'RHH'). In 2020, this taxon was described as a species in its own right: N. diabolica.Bianchi, A., C.C. Lee, M.R. Golos, F.S. Mey, M. Mansur, Y.M. Mambrasar & A.S. Robinson 2020. Nepenthes diabolica (Nepenthaceae), a new species of toothed pitcher plant from Central Sulawesi. Phytotaxa 464(1): 29–48. Like the type form of N. hamata, N. diabolica has been raised to flowering size in cultivation and used to make hybrids with other Nepenthes species.[Anonymous] 2013. Nepenthes Growers Newsletter 2(1): 3.
Later developments British geographer Stewart McPherson published an updated description of the species in his 2009 monograph, Pitcher Plants of the Old World. The book also covered the closely related undescribed taxon N. sp. Sulawesi, which McPherson had observed with Greg Bourke in 2007. Nepenthes sp. Sulawesi was described as N. nigra in McPherson's 2011 work, New Nepenthes.
Description
Nepenthes hamata is a strong climber. The stem, which may be branched, reaches a maximum length of around 7 m. It is terete to obtusely trigonous and varies in diameter from up to 3 mm in rosettes and short stems, to 4–5 mm in climbing stems. In the former, the internodal length is typically up to 6 mm and in the latter 3.5–6 cm.
Leaves Leaves are sessile and chartaceous in texture. The shape of the lamina (leaf blade) is variable: it may be linear, lanceolate, or slightly elliptic.
In the case of rosettes and short stems, the lamina is typically oblanceolate to oblong-elliptic and measures up to 7.5 cm in length by 2.5 cm in width. It has an acute apex and does not exhibit a peltate tendril attachment. The laminar base is amplexicaul, clasping the stem and giving it a subperfoliate appearance. Auricles may be present, although their level of development varies. The lamina may be slightly decurrent down the stem, but not prominently so.
Laminae produced on climbing stems are predominantly oblong-elliptic in shape, but may rarely be lanceolate. They are larger than those borne on shorter stems, but nonetheless relatively short, measuring 5–15 cm in length by 1.8–4 cm in width. The laminar apex may be acute to obtuse, while the base is abruptly contracted and clasps the stem; it may be decurrent for up to 1.5 cm in some populations. Two (rarely up to four) longitudinal veins are present on either side of the midrib. They are restricted to the outer third to half (rarely up to two-thirds) of the laminar surface. Pinnate veins are inconspicuous; they are patent and branching.
Pitchers Rosette and lower pitchers are only produced for a short time before the plant transitions into a scrambling vine (although they may be produced later on offshoots from the original stem). They grow up to 18 cm high by 5 wide. They are ovate in the basal fifth to half of the pitcher cup, being bulbous to varying degrees in this portion, often narrowly so. The pitcher is narrower in the upper part and may be cylindrical or slightly infundibular towards the orifice. The boundary between these two portions is often delineated by a pronounced hip. The ventral face of the pitcher is flattened. A pair of wings up to 16 mm wide runs down the ventral surface of the pitcher cup. These wings bear densely packed filiform fringe elements up to 19 mm long, which commonly exceed the width of the wings themselves. These filaments are often arranged in pairs, spaced around 2 mm apart, and are usually branched dichotomously once or twice. The waxy zone of the inner surface is well developed.Bauer, U., C.J. Clemente, T. Renner & W. Federle 2012. Form follows function: morphological diversification and alternative trapping strategies in carnivorous Nepenthes pitcher plants. Journal of Evolutionary Biology 25(1): 90–102.