P. C. BOYCE, S. Y. WONG, A. P. J. TING, S. E. LOW, S. L. LOW, K. K. NG, l. H. 001, 2010 3 The Araceae of Borneo-The Genera Peter C. Boyce Visiting Scientist Pusat Pengajian Sains Kajihayat [School Of Biological Sciences] Universiti Sains Malaysia 11800 USM, Polau Pinang, Malaysia [email protected] Wong Sin Yeng, April Ting Pei Jen, Low Shook Eng, and Low Shook ling Department of Plant Science & Environmental Ecology Faculty of Resource Science & Technology Universiti Malaysia Sarawak 94300 Kota Samarahan, Sarawak, Malaysia [email protected]; [email protected]; [email protected]; shookling5052@ho~com Ng Kiaw Kiaw and Ooi 1m Bin School of Biological Sciences Universiti Sains Malaysia 11800 Penang, Malaysia [email protected]; [email protected] ABSTRACT flora for Borneo quite likely exceeds 1,000 species, with barely one third of these A summary of the aroids of Borneo of the described. Borneo is an aroid habitat of rank of genus and above is offered. 36 global significance, and arguably one of the genera are listed, of which 35 are indige­ richest and diverse on the planet. World nous, and one (Typhonium Schott) genu­ and Bornean taxonomy and ecology are inely naturalized. Of the 35 indigenous briefly outlined, along with a summary of genera, eight (Aridarnm Ridl., Bakoa the history of aroid fieldwork in Borneo. P.C.Boyce & S.Y.Wong, Bucephalandra The most recent key literature is cited, and Schott, Ooia S.Y.Wong & P.C.Boyce, Ped­ keys to Bornean aroid taxa of genus and icellarnm M.Hotta, Phymatarnm M.Hotta, above are presented. Most genera are Pichinia S.Y.Wong & P.C.Boyce, and illustrated. Schottariella P.C.Boyce & S.Y.Wong) are Bornean endemics. Four additional genera PREAMBLE (Caladium Vent., Dieffenbachia Schott, Syngonium Schott, and Xanthosoma The aroid flora of Borneo is one of the Schott) are listed as adventives. The aroid richest on the planet, comprising at least flora of Borneo currently stands at 670 670 species (Boyce, Croat & Wong, unpub. indigenous species, of which more than data), of which approximately 40% remain 40% are undescribed novelties, and with to be described. Remarkably, these data are this figure based significantly on our based significantly on our understanding of understanding of the flora of Sarawak, the flora of Sarawak, Sabah and Brunei (Le. Sabah and Brunei (Le. less than one third less than one third of the total landmass). of the total landmass). Kalimantan, com­ Kalimantan, comprising more than 70% of prising more than 70% of the land area of the land area of Borneo, remains very Borneo remains very poorly known, and poorly known, and undoubtedly harbors undoubtedly harbors a great many novel a great many novel species. We estimate species. It is estimated that the total aroid that the total aroid flora for Borneo quite 4 AROIDEANA, Vol. 33 likely exceeds 1,000 species, with barely Europe until he and his family were one third of these described. In short, murdered during a local uprising at the Borneo is an aroid habitat of global start of the Bandjermasin War. significance, and arguably one of the Englishman Hugh Low (later Sir Hugh richest and most diverse on the planet. Low) came from a significant family of nurserymen in Clapton, north London, and mSTORY OF AROID RESEARCH initially arrived in Sarawak, Borneo in early FIElDWORK IN BORNEO 1845 on a commission from the Honorable East Indian Company, soon resigned and Over the past almost two centuries became secretary to James Brooke (the first Borneo has been witness to numerous of Sarawak's 'White Rajahs'). He later expeditions which undertook significant explored the Sarawak river and many of sampling of biodiversity, as well as many its tributaries before traveling to Labuan in specifically plant-related excursions, usual­ modem-day Sabah, where he was to be ly by individuals. Thus our knowledge of based from 1848-1877, and from where he the aroids of Borneo, such as it is, is based made many excursions, including the first in part on data and samples gathered by European ascent of Mt. Kinabalu. Although field naturalists with varying levels of Low's main interest was orchids, during his interest in the family. travels he collected numerous aroids, many Among the earliest collecting in Borneo of which he shipped living to the family pertinent to aroids was that by the Dutch company in England. botanist Pieter Willem Korthals (1807- In terms of land area covered the most 1892). Korthals arrived at Banjarmasin, in extensive explorations ever of Borneo what is now South Eastern Kalimantan remain those of Anton Willem Nieuwen­ Selatan in late July 1836, and explored the huis (1864-1953), a surgeon in the Dutch region until mid-December of the same East Indian Army, and later Prof. of year. His collections were deposited in the Ethnology of the Dutch East Indies. Nieu­ Leiden Herbarium, Netherlands, with in­ wenhuis traveled extenSively through what complete sets sent to Buitenzorg Herbari­ is now Kalimantan between 1896 and 1934. um (now Herbarium Bogoriense) in Java, His expeditions are especially notable for and to various herbaria in Europe. the quantity of living plants, collected Next on the scene was Yorkshireman mainly by his European assistants, particu­ James Motley (1822-1859) who went to larly Johann ('Hans') Gottfried Hallier Labuan (an island in the Bay of Brunei, (1868-1932) and later Gustaaf Adolf Fre­ between modem Brunei and the Malaysian derik Molengraaf (1860-1942), and Indo­ state of Sabah) in 1849 to pioneer coal nesian mantris, and sent to Buitenzorg mining and other enterprises for the (Bogor) Botanical Gardens, Java, to be Eastern Archipelago Company. Although cultivated. These living collections signifi­ Motley did not have a good relationship cantly assisted Alderwerelt and Engler in with Hugh Low, the other naturalist in their studies. Nieuiwenhuis' herbarium Labuan at the time, he corresponded with collections were deposited in Bogor and numerous botanists, especially William Leiden. Jackson Hooker at Kew Gardens and Despite the preceding activities, it can notably Heinrich Wilhelm Schott in Vienna. still be fairly said that the history of After Motley quit the Eastern Archipelago intensive systematic aroid research in Bor­ Company in 1853 he spent time on neo begins with the extraordinary activities Singapore and in exploring the coast of ofItalian naturalist Odorado Beccari (1843- Sumatera, before being employed as su­ 1920). While best remembered for his work perintendent of the private Julia Hermina on palms (Arecaceae), a group in which he coal mine at Bangkal south-east of Banjar­ specialized throughout most of his adult masin. From here he continued to send life, through his prodigious collecting plant material, including living aroids, to activities, Beccari made significant contri- p. C. BOYCE, S. Y. WONG, A. P. J. TI G , S. E. LOW, S. L. LOW, K. K. NG, I. H. 001, 2010 5 Plate 1. Lemnoideae. A. Lemna aequinoctialis Welw. B. SpiTOcle/a poly rrbiza (1.) Schleid. Note the multiple roots emerging from each plant body and the reddish coloration. C. Minute W'o/Ifia glohosa (Roxb.) Hartog & Plas surrounding Spiracle/a po/yrrhiza. D. Lemna minor L. 6 AROlDEAi\)A, Vol. 33 Plate 2. Potheae: Pothos L. A & B: Pathos atropurp urascens M.Hotta. A: Note the diagnostic large, inflated, lavender spathes. B. Spadix detail s w ith the tepals clearly visible aro und each fl ower. C: Pathos min:thilis Merr. C. Freshly opened inflo rescence. Over the next few days the spadix wil l extend to double the pictured length . D: Pathos insignis Eng!. P. C. BOYCE, S. Y. WONG, A. P. J. TING, S. E. LOW, S. L. LOW, K. K. NG, I. H. 001, 2010 7 butions to numerous other plant families, administering the often enormous areas in particular the aroids (Araceae), for which under their jurisdiction and exploring the family he is famous for introducing to abundant wildlife. Charles Hose, sent to Europe the Titan Arum (Amorphophallus Sarawak as a trainee cadet under the Rajah titanum (Becc.) Becc.) from Sumatera in Sir Charles Brook, arrived in Sarawak in 1878. The imagination-capturing nature of 1884 and was in 1888 stationed in Baram, in this indisputably remarkable plant has, the even now remote N.E. ofthe state. Hose somewhat regrettably, overshadowed Bec­ was eventually to spend over 25 years in cari's exemplary aroid work in Sarawak, Sarawak, of which 20 years was spent in when through general collecting from Baram. Among Hose's remarkable feats 1865-1868 he made the first significant were the exploration of the Hose Moun­ gatherings of the extraordinarily rich aroid tains, the range that separates the valleys of flora of N.W. Borneo at a time when the Rejang and Baram rivers, and the first virtually every aroid he touched was new extensive exploration of the limestone to science. systems of Niah, among much else. Al­ The bulk of Beccari's Bornean aroid though not specifically an aroid collector, material was worked up by Engler, primar­ the very nature of Hose's fieldwork in ily in the Bullettino della Reale Societa botanically unexplored areas netted many Toscana di Orticultura (Engler, 1879a), the novel collections. These were later worked Botanische JahrbUcher fur Systematik, up by Rendle (1901). Pjlanzengeschichte und Pjlanzengeogra­ The next person to visit Borneo, specif­ phie (Engler, 1881), and in Beccari's Malesia ically Sarawak, with a particular interest in (Engler, 1883), with additional taxa and aroids was Henry Nicholas Ridley (1855- notes appearing in Monographiae Phaner­ 1956). Ridley, a prodigiously productive ogamarum (Engler, 1879b), and Das Pflan­ botanist, made a series of visits to Borneo zenreich (Engler, 1912). Beccari himself between 1893 and 1915 and through the wrote up several aroid species (Beccari, resulting publications (in particular Ridley, 1879, 1882).