BLUMEA 42 (1997) 1-106 A skeletal revision of Nepenthes (Nepenthaceae) Matthew Jebb & Martin Chee k Summary A skeletal world revision of the genus is presented to accompany a family account forFlora Malesi- ana. 82 species are recognised, of which 74 occur in the Malesiana region. Six species are described is raised from and five restored from as new, one species infraspecific status, species are synonymy. Many names are typified for the first time. Three widespread, or locally abundant hybrids are also included. Full descriptions are given for new (6) or recircumscribed (7) species, and emended descrip- Critical for all the Little tions of species are given where necessary (9). notes are given species. known and excluded species are discussed. An index to all published species names and an index of exsiccatae is given. Introduction Macfarlane A world revision of Nepenthes was last undertaken by (1908), and a re- Malesiana the gional revision forthe Flora area (excluding Philippines) was completed of this is to a skeletal revision, cover- by Danser (1928). The purpose paper provide issues which would be in the ing relating to Nepenthes taxonomy inappropriate text of Flora Malesiana.For the majority of species, only the original citation and that in Danser (1928) and laterpublications is given, since Danser's (1928) work provides a thorough and accurate reference to all earlier literature. 74 species are recognised in the region, and three naturally occurring hybrids are also covered for the Flora account. The hybrids N. x hookeriana Lindl. and N. x tri- chocarpa Miq. are found in Sumatra, Peninsular Malaysia and Borneo, although rare within populations, their widespread distribution necessitates their inclusion in the and other and with the of Flora. By large hybrids are rare sporadic, exception N. x kinabaluensis, which forms a discrete hybrid swarm on Mt Kinabalu. Six new species are described: Nepenthes argentii from the Philippines, N. aristo- lochioides from Sumatra, N. danseri from Waigeo Island (New Guinea), N. diatas from Sumatra, N. lamii from New Guinea, and N. murudensis Culham ex Jebb & Cheek from Sarawak. One new combination is made; N. macrophylla (Marabini) of edwardsiana f. Jebb & Cheek, formerly a subspecies N. Low ex Hook. Three species synonymised by Danser (1928): N. eustachya Miq., N. ramispina Ridl., and N. sumatrana (Miq.) Beck, and one synonymised by Macfarlane (1908): N. hispida Beck, are restored. Nepenthes pectinata Danser is also restored. A num- ber ofnames are relegated to synonymy, and lectotypifications have been undertaken where necessary. 1) Department of Botany, Trinity College, Dublin 2, Ireland. 2) Herbarium, National Botanic Gardens, Glasnevin, Dublin 9, Ireland. 3) Royal Botanic Gardens, Kew, Richmond,Surrey, TW9 3AB, U.K. 2 BLUMEA Vol. 42, No. 1, 1997 Like Danser we recognise no subspecies or varieties. Collections remain few, with 9 species being known from the type collection alone. A further 10 species are mountain and 10 of the restricted to single mountains, or groups, only remaining taxa extend beyond a single island. Eight species of Nepenthes do not occur in the Flora Malesianaregion: Nepenthes madagascariensis Poir. and N. masoalensis Schmid-Hollinger in Madagascar, N. per- villei Blume in the Seychelles, and N. distillatoriaL. in Sri Lanka. In Northern India N. khasiana Hook. f. and in Indochina N. anamensis Macfarl. and N. thorelii Le- comte. Nepenthes vieillardii Hook. f. is found in New Caledonia(specimens from New Guinea formerly placed in this species are now placed in the new species N. lamii). PREVIOUS REVISIONS There have been three major monographic revisions of the genus. Firstly Joseph Hooker's 1873 account in De Candolle's Prodromus, at which timethe genus num- bered 33 species. He placed the Seychelles species N. pervillei in a monotypic sec- tion Anourosperma. Macfarlanerevised the family for Engler's Pflanzenreich (1908), recognising 58 species. Danser's treatment of the genus for the Netherlands Indies former treated 51 species found in the Dutch East Indies and adjoining areas. Historically, Nepenthes taxonomy has bothbenefited and suffered from the horti- of these and often entered herbariavia the cultural desirability plants, species green- houses of Europe. Collectors of type material such as David Burke (1880), Charles Curtis (1878-84) and Frederick Burbidge (1877-78) were also collectors of live plants for Mr. Harry Veitch of Chelsea, one of the foremost growers of Nepenthes at that time. Bull Nurseries were also in the trade at the time, and their catalogues list an impressive range of species at outrageous prices. Sir Hugh Low, who was Rajah James Brooke's personal secretary at this time, sent many plants to his father at the Clapton nurseries in London. Maxwell Masters and Frederick Burbidge appear to have been regular correspon- dents of Hooker his had Sir Joseph at Kew, soliciting opinion on specimens they growing in nurseries. During this period (1881-1890) a number of species and culti- vars were published in the Gardeners' Chronicle. This led to uncritical descriptions, as well as unsatisfactory informationon provenance (N. burkei Mast., N. curtisii Mast, and N. stenophylla Mast, were all based on cultivated material alone). Withoutdoubt Danser's masterful treatment in 1928 remains the most thorough, and up to date treatment of the genus. He retained 35 species in the former Dutch then world total of 65 East Indies and adjoining areas, adding 17, to give a spe- cies. He made a first attempt at a phylogenetic treatment, with six informal species groups. TAXONOMY SINCE DANSER Littlecollecting has occurred since Danser's revision (1928), and it was not untilthe 1970's and 80's that specialist collectors began publishing new species on an ad hoc basis. Horticultural interest in these plants has been the most important factor in stim- ulating this progress. Since Danser (1928), 36 names of species, subspecies, and M. Jebb & M. Cheek: Skeletal revision of Nepenthes 3 naturally occurring varieties and hybrids have been published (including two further species by Danser); 18 ofthese areretained here. A numberof species names remained for numberof adnata Tamin invalidly published a years (N. & M. Hotta ex Schlauer, N. dentata Sh. Kurata, N. globamphora Sh. Kurata & Toyosh. and N. macrovulgaris J.R.Turnbull& A.T. Middleton). In 1984, two sets of competing names were published for three Sulawesi species. On the 6th February, Kurata (1984a) published N. eymae and N. rubromaculata (a homonym of a nineteenth century hybrid). On the 10th February Turnbull and Mid- dleton (1984) published N. glabrata (a valid name for N. rubromaculata), N. hamata and N. infundibuliformis (= N. eymae). On the 7th March, Kurata (1984b) published N. dentata(=N. hamata). The question of dates is complicated by the fact that the first two publications were subtitled with the claimthat they were 'preprinted'. The ac- tual dates at which these publications were 'widely' available is difficult to determine, and it is unclear whether the Turnbull and Middletonpre-publication was in fact dis- tributed beforeeither of Kurata's publications. Several regional revisions have appeared, including Kurata's Nepenthes ofMount Kinabalu(1976), Shivas's Pitcher Plants of Peninsular Malaysia & Singapore (1984), Tamin & Hotta's Nepenthes di Sumatera(1986), Jebb's Nepenthes in New Guinea (1991) and Phillipps & Lamb's Pitcher Plants of Borneo (1996). Jumaat Adam has revised the Bornean species, but his species descriptions are scattered in the litera- ture, and no review of the entire flora has been undertaken except in the form of an ecological paper (Adam et al., 1992). HORTICULTURE AND HYBRIDS There are a large numberof collectors and growers of Nepenthes and many species are now widely cultivated. Several newsletters and an electronic bulletin board (CP, served by [email protected]) are dedicated to the cultivation and descrip- tion of carnivorous plants. A numberof new species, as well as numerous cultivars, have been described in these newsletters. Nepenthes cultivation last reached a zenith at the end of the 19th century. Pollen and seed exchange is now common practice in both conserving species and developing new hybrids. The entire genus is listed under Appendix II of the CITES convention, and two species (N. khasiana and N. rajah) are listed as Appendix I species. Nepenthes rajah and N. the known be clipeata are only species to directly endangered by specialist col- lectors. Over 280 have been 193 than hybrid names published, involving more two par- ents. 34 species are involved in these crosses, although 75% of the crosses involve N. rajflesiana and/or N. maxima. Some hybrids have been generated through multi- ple crosses of up to six species (Schlauer, 1994). ECOLOGY Nepenthes species occur mostly locally, often sporadically, and then often in large numbers. They are found from sea-level to 3,500 m, but most commonly between 1,500 to 2,500 m. They can be found in practically every vegetation type, but espe- 4 BLUMEA —Vol. 42, No. 1, 1997 cially on thin or infertile soils (either from chemistry, waterlogging or low nutrient for- levels), where the canopy is sparse or thin. They occur least commonly in closed white leached est. They are common on podsolic soils, wet peaty soils, or heavily volcanic soils, but are almost entirely absent from rich alluvial or clay soils. They are commonly encountered along river banks, on abrupt, open, or rocky ridge tops, and in wet mossy forest. A number of taxa are restricted to ultrabasic, serpentine soils (N. argentii, N. burbidgeae, N. danseri, N. x kinabaluensis, N. macrovulgaris, N. rajah and N. vil- losa), whilst others appear to be restricted to limestone rocks ( N. campanulata, N. mapuluensis, and N. northiana). found in a wide of habitats, and thrive best Some species are range appear to in mirabilis few surviv- disturbed habitats (N. and N. gracilis). A species are capable of ing in quite dense shade (N.