Gardens'Bulletin Singapore56(2004) 153-159. 153 A new species ofAmorphophallus (Araceae: Thomsonieae) from Sarawak, Borneo LB. IPOR1 CS.TAWAN1 AND P.C. BOYCE2 , & faculty ofResource Science Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak 2 Malesiana Tropicals, Suite 9-04, Tun Jugah Tower, No. 18, Jalan TunkuAbdul Rahman 93100 Kuching, Sarawak, Malaysia Abstract AmorphophallusjulaihiiIpor,Tawan&P.C. Boyce anew speciesfromforested limestonein Mulu NationalPark, Sarawak, Borneo is described and illustrated. Introduction Recognition ofAmorphophallusjulaihii as a new species takes to fifteen the number of indigenous species of Amorphophallus recorded from Borneo (Bogner 1989; Hetterscheid 1994, 2001). IncludingA.julaihii there are eight & species in Sarawak, viz:A. angulatusHett. A.Vogel,A. brachyphyllusHett., & A. eburneus Bogner, A. hewittii Alderw., A. hottae Bogner Hett., A. infundibuliformisHett.,A. Dearden &A. Vogel, A.pendulusBogner& Mayo. Five species have been recorded from Sabah: A. hottae, A. lambii Mayo & & & Widjaja, A. rugosus Hett. A.L. Lamb., A. tinekeae Hett. A. Vogel andA. venustusHett.,A. Hay &J. Mood. Eightspecies arerecordedfromKalimantan: & A. borneensis (Engl.) Engl. Gehrm., A. costatus Hett., A. hewittii, A. infundibuliformis,A. lambii, A. linguifonnis Hett., A. pendulus andA. prainii Hook./, (the last perhaps based on a mis-labelled specimen; A. prainii is otherwise known only from Peninsular Malaysia and Sumatera). With the exception ofA. prainii all Bornean Amorphophallus are endemic to Borneo. The most remarkable aspect of these data is that 13 of these 15 species have been described within the past 25 years. This extraordinary increase in recognized species is being repeated throughout the range of the genus such that Amorphophallus now numbers over 200 species, of which in excess of one third are novel taxa described since 1980. Recent and on-going fieldwork indicates that there are more novel Bornean Amorphophallus awaiting description. 154 Gardens'BulletinSingapore56(2004; Ecology ofAmorphophallus in Sarawak Two of the authors (I.I. & P.C.B.) have been observing Amorphophallus populations in North Borneo formany years and basedon these observed data thefollowing summary ofAmorphophallusecology in Sarawakmay bedrawn. Five of the eight Sarawak Amorphophallus species occur in limestone forest with three, A. brachyphyllus, A. eburneus and A. julaihii, seemingly restrictedto this habitat.AmorphophallusbrachyphyllusandA. eburneusoccur sporadically andallopatrically onboth the Bau andPadawan limestones.There are also records of A. brachyphyllus from the Mulu and Niah limestones, although these records have yet to be verified and it is quite possible that the Mulu and Niah plants represent one or more additional undescribed vicariant taxain the species-richMantaGroup (Hetterscheid, inprep.). The singlerecord from Mulu for the otherwise Sabahan A. hottae also requires verification not least because in Sabah A. hottae is never associated with limestone. Amorphophallushewittii ascurrently circumscribedis frequently found in association with limestone, occurring commonly on both the Bau and Padawan limestones where the flowering of large specimens occasionally receives coverage in the local press. However, A. hewittii is not restricted to calcareous rocks, and is also found on the hard sandstones of the Penrissen Range and occurs in several widely scattered, mostly sandstone, locations throughout Sarawak. It should be noted that this apparent ecological diversity may be an artifact of imperfect taxonomy. The large size of this plant, both florally andvegetatively, makesitanunpopularsubjectforherbariumcollection andourknowledgeofitsmorphology isbasedon adecidedlymeagrecollection ofmediocre specimens. All other Sarawak species appear to be sandstone or shale associated. Amorphophallus pendulus, described from Gn. Matang (Bogner etal. 1985), is widespread and frequently locally common on moist sandstones at least as far east as Kapit (Belaga) (Boyce, pers. obs.). Amorphophallus infundibuliformis is widespread but scattered and seldom locally abundant in Kuching and Sri Aman Divisions, with collections known from wet but well- m & drained sandstone sites between 60-870 asl in Lundu. Padawan, Bau Ulu Batang Ai. Amorphophallus angulatus was described from the sandstones of Gunung. Selantik (Sri Aman), is also recorded from Gunung. Ampungan (Samarahan) and has recently been discovered at NangaGaat (Kapit) where it occurs on hard shales exposed by stream action (Boyce, pers. obs.). Relationships ofAmorphophallusjulaihii Amorphophallus julaihii fits uncontroversially into Hetterscheid's 'Manta Group' (Hetterscheid, in prep), into which also belong all the other Sarawak AnewspeciesofAmorphophallus(Araceae:Thomsonieae)fromSarawak,Borneo 155 Figure 1.Amorphophallusjulaihii Ipor, Tawan & P.C. Boyce.A. seedling, B. leaflet of seedling, C. mature plant, D. tuber with adventitious roots, E. tuber frominflorescence, F. leaflets ofmatureplant, G.inflorescencewithcataphylls, H. L S. ofthe inflorescence, I. male andfemalezones, J. stamens, K. pistils, L infrutescence with berries, M. berry and in L.S.. A,B, C & D, E, F, G, H, I, J, K from CST 2527, L & M from CST 2530 - drawings from fresh samples. 156 Gardens'BulletinSingapore56(2004) species to which A. julaihii is most similar. The Manta Group is defined as: Small to medium-sized herbs with tubers depressed-globose or subglobose that are not offsetting; petioles sometimes forming an intercalary bulbil at the junction with the lamina (A. angulatus). Seedling leaves often flushed with dark red or lilac-red (A. angulatus, A. pendulus, - Boyce, pers. obs.) Spathe linguiform, narrow or broad. Spadix shorter than or only slightly longer than spathe. Male flowers often longitudinally elongate and fused into rows. Amorphophallus julaihii Ipor, Tawan et P.C. Boyce sp. nov. Ab omnibus speciebus in habitu calcicola lithophytica Borneensibus borealis spathaparva in toto atropurpureis differt. Typus. Sarawak, Miri Division, Mulu National Park, forest on limestone, C.S. Tawan & LB. Ipor CST 2527, 14 April 2004 HUMS (Holotypus: (Herbarium Universiti Malaysia Sarawak) inflorescence andtubersinspirit; vegetativeparts (petiolewithleaflets, seedlings)-herbarium specimens.) Small tomedium-sizedherb, 50-100cmtall. Tuberdepressedsub-cylindrical to globose, with irregularraisedareas, up to5.8cmdiam., 6.0cmhigh, surface dull brown greyish, innerpart fleshy, whitish. Adventitious root scars present on top portion of tuber at flowering stage, new roots developing during vegetative stage. Petiole up to 44 cm long, c. 19 mm diameter at base, turgid, cylindrical, smooth,brightgreen, envelopedbasallybydrieddecayingbrownish cataphylls; lamina highly dissected, rachises naked, narrowly channelled, yellowish green; leaflets elliptic-lanceolate, 11.0-13.0 x 4.0-4.4 cm, some petiolulate, petiolule 1.5-3.0 cm long, slightly channelled adaxially. ultimate leaflet sessile, leaflets asymmetrical, apex apiculate 1.5-2.0 cm long; base unequal; margin slightly wavy andsparsely fine-toothed; adaxial surfacebright green, thin slightlyleathery, abaxial surfacepalegreen;6-16pairsofsecondary veins with intermediate veins per leaflet, these adaxially channelled and adaxially raised; venation forming distinct submarginal veins; tertiary veins reticulate; lamina texture leathery when fresh, chartaceous when dry. Inflorescence solitary, flowering withoutfoliage leaves;pedunclecylindrical, up to 17.5 cm long, 8-9 mm diam. at base, yellowish to creamy. Cataphylls 6: first 1-4 ovate to linear, 3-13 cm x 1.5-2.0 cm, brownish to dark brown, thin, soon withering anddecaying; thenext 5-6 linear-oblong, 15-21 x 2.4-3.5 cm, lightpurplish to whitish andslightly purplish stained. Spathe elongate-oblong, limberect at anthesis. laterrecurvedandtwistedtowards the base, up to 12 cm long, width at base 4.0 cm, at middle 4.0 cm, at apex 4.5 cm, lower spathe strongly convolute andforming ashorttube 3.5-4.0cmlong; innersurface of upper spathe limb ribbed with distinct venation, purplish, lower part rough and verrucose, deep purple; outer surface of upper spathe limb with distinct longitudinal venation, margin thinly undulate, apexdentate; upperpartofspathe AnewspeciesofAmorphophallus(Araceae:Thomsonieae)fromSarawak,Borneo 157 — Inflorescence (scalebars 6 cm) Spathe (Scale bars -4 cm) a. Spathe and spadix, b. Infrutescence. Male and female zones ofthe spadix (Scale bars-2 cm) (Scale bar-2 cm) Figure 2.Amorphophallusjulaihii Ipor, Tawan & RC. Boyce 158 Gardens'BulletinSingapore56<2(X)4) limb rich purple-scarlet, middle part and margins darker. Spadix exceeding spathe, 18.5-19.0 cm, short stipe, 1.0-1.5 cm long. Appendix up to 14 cm mm mm long, cylindrical, spongy, purplish, 9-9.2 diam. at base; 7.5 diam. at mm middle, 2 diam. atapex, surfaceverrucosewithlongitudinal lines, appendix producinganunpleasantodoursimilartothatofrottenfish.Flowers unisexual; male zone cylindrical, up to 3 cm long, 9 mm diam. at middle, whitish to mm mm creamy; stamens connate and short, c. 1 long, c. 0.5 broad across, fusedwithadjacentstamens, filaments c. 5 mm, truncate,pores apical, rounded or variously elongate, yellowish or creamy, pollen brownish. Female zone cylindrical, separated by irregular zone ofsterile stamens from the male zone, 1.5-2 cm long, 10 mm diameter; pistils in irregularly rows, rather lax, mm sometimes almost in V-shaped rows; ovaries ovoid-subglobose, 2.5-3.0 mm in long, 1.8-2.0 broad at base, dark purple, unilocular rarely bilocular; stigma sessile, two to three lobed or sometimes irregularly lobed, Infructescence with up to 35 berries, pedunculate up to 22 cm long, 6 mm mm diam. at base, 9 diam. at apex, with blackish-dark brown V-shaped scar from the marcescent spathe, basally with remains of the cataphylls. Berries when ripe deep orange, ellipsoid 15-16 mm x 8-10 mm, apex rounded, with mm blackish stigma remnants, one seeded. Seeds ellipsoid, 12-14 x 7-8.2 mm wide, testa smooth, thin, yellowishgreen, seedcopiously starchy, embryo small. Distribution: Endemic in Sarawak, so far recorded only from Mulu National Park, Miri Division. Ecology: Limestone forest, growing in shady areas, in humus-filled fissures and holes in limestone. Flowering recorded in April. Notes: Amorphophallus julaihii is most similar to A. angulatus, A. brachyphyllus and A. eburneus, (all Sarawak) and A. costatus (Kalimantan). FromA. angulatus (with whichA.julaihii shares apurple spathe), itdiffers by the spadix appendix exceeding the spathe and by the smaller, not diamond- shaped male flowers. From A. eburneus and A. brachyphyllus (also both restrictedtolimestone),A.julaihiiisimmediatelyseparablebythepurpleribbed spathe. The resemblance of A. julaihii to A. costatus is in having an erect elongate triangular spathe with the base strongly convolute forming a narrow tube. Inboth species, the spadixexceedsthe spathebutinA.julaihiithe spadix is shortly stipitate while it is sessile in A. costatus; the male zones in both species are similar - cylindrical, flowers slightly distinct, irregularly arranged orinlongitudinaloblique,interruptedrows.Thematt-purplespatheofA.julaihii readily separates it from A. costatus in which the spathe interior is glossy maroon. To dateA. costatus is recorded only from southern Kalimantan. AnewspeciesofAmorphophallus(Araceae:Thomsonieae)fromSarawak,Borneo 159 Etymology:This speciesisnamedafterMr. JulaihiAbdullah, Deputy Research Manager of Sarawak Forestry Corporation, who first showed the first two authors this species in the Mulu National Park, Sarawak. He was formerly Botanist ofthe Sarawak Forest Department, Kuching. Other specimens seen: Type locality, inflorescence, C.S. Tawan & LB. Ipor CST 2528, 14 April 2004 (HUMS); Type locality, inflorescence, C.S. Tawan & LB. IporCST 2529, 14April 2004 (SAR); Type locality, infructescence in spirit C.S. Tawan & LB. Ipor CST 2530, 14 April 2004 (HUMS); Sarawak, Miri Division, Mulu National Park, unspecified locality, J.Brodie AM-39, 12 May 1999 (SAR). Acknowledgements The first two authors thank Universiti Malaysia Sarawak for the grant to undertake this project. All authors would also like to thank the Director of Sarawak Forest Department forpermission to collect the specimens, and also toJulaihiAbdullah, SulaimanJamhari, MalcomDemies,MeekiongKalu,James Abai, Mohd. Rizan Abdullah, Hidir Marzuki and Sekudan Tedong for their help. Our appreciation also goes to Joseph Pao for the botanical illustrations. References Bogner,J. 1989.AnewAmorphophallus(Araceae)fromSarawak. Willdenowia 18: 441-443. Bogner, J., S. Mayo and M. Sivadasan, M. 1985. New species and changing concepts in Amorphophallus. Aroideana 8: 14-25. Hetterscheid, W.L.A. 1994. Notes on the genusAmorphophallus (Araceae)-2. New species from tropicalAsia. Blumea 39: 237-281. Hetterscheid, W.L.A. 1994. Notes on the genus Amorphophallus (Araceae) - 11. New and obsolete species from East Malaysia and continental Southeast As\a..-Blumea 46: 253- 282.