Araceae Juss.

Alocasia chaii P.C.Boyce

This species is accepted, and its native range is Borneo (Sarawak).


CATE Araceae, 17 Dec 2011.

Sarawak, Kapit Division, to date known only from the foothills of Gunung Bukit Batu, Hose Mountains and Ulu Kapit.
Alocasia chaii belongs to the informal Alocasia scabriscula group (see Hay, 1998), notable for coriaceous, leathery to subsucculent leaves and the spathe usually constricted at a level above the sterile interstice of the spadix, thus, including the all or at least the majority of male flower zone within the lower spathe. Alocasia chaii is most similar to A. scabriscula N.E.Br. in overall morphology, differing in the considerably smaller, but hardly less robust habit, the peltate leaves and the persistent lower spathe that turns bright magenta at fruiting. In general stature and by the grey leaves A. chaii also vaguely resembles Sabahan A. melo A.Hay, P.C.Boyce & K.M.Wong, although the latter is readily distinguished by the rugose and bullate adaxial lamina surface and the fruiting spathe white with slight red speckling. Alocasia melo is confined to ultramafic substrates.
General Description
Small robust herb to ca 40 cm tall, stem shortly erect to decumbent, eventually forming a short rhizome; wild plants with rather few leaves (up to 4, usually less), cultivated plants with several leaves (up to 7); petioles stout, ca 20 cm long, sheathing in the lower ca 1/4, puberulent, pale green with scattered deep red spots and  speckles in the lower half; sheath persistent, more or less closed; lamina broadly ovato-elliptic, up to 40 cm long but frequently much less and typically reaching c. 23 cm x 10−15, exceptionally up to 25 cm wide, thickly coriaceous to subsucculent, almost completely peltate save for a shallow retuse notch between the tips of the connate posterior lobes, margins reflexed to form a raised smooth rim abaxially, apex acute to obtuse and mucronate for ca 1 cm, lamina adaxially pale matt grey, abaxially greenish white, anterior costa with 1−3 primary lateral veins on each side, diverging at ca 90° (proximal ones) to 30° (distal ones); primary veins adaxially somewhat raised proximally to the mid-rib and impressed distally, flush to very slightly impressed with deep red axillary glands abaxially; secondary venation impressed adaxially, more or less flush with the lamina abaxially, forming defined interprimary collective veins when fresh, this decidedly obscure in dried material; posterior lobes about 1/3 – 1/4 the length of the anterior, with the posterior costae diverging at ca 30°; inflorescences several together (up to 4 on vigorous plants), each subtended by a short, broad prophyll and a single cataphyll; peduncle short, more or less hidden within cataphyll; spathe ca 7 cm long, externally white with a scattered red flecks on the lower part, interior uniformly glossy white; lower spathe 2.5−3.5 cm long, ovoid, separated from limb by a rather weak oblique constriction; limb erect even after anthesis, narrowly lanceolate-triangular, 3−5 cm long; spadix ca 2/3 the length of the spathe, ca 4.5 cm long, briefly stipitate; stipe cylindrical, ca 2−5 mm tall, glossy white; female zone about 1/4 of the length of the spadix, pistils moderately densely arranged;  ovaries ovoid, ca 1.5 mm diam., facing diagonally up, pale greenish white; style more or less absent; stigma white, single, bilobed, sometimes trilobed (all variations present in a single inflorescence); sterile interstice absent or represented by a few (less than 5) synandrodia; male zone held entirely within the lower spathe, cylindric to barrel-shaped, about 1/4 the length of the spadix, about 2/5 as wide as long, ivory; synandria densely arranged, more or less square in plan view, ca 1.5 mm wide, the thecae very slightly overtopped by synconnective; appendix about 1/3 of the length of the spadix, narrowly conic; fruiting spathe broadly ovoid, c. 2.5 cm long, erect, glossy brilliant magenta with a few scattered darker spots and streaks at fruit maturation, then splitting longitudinally into several unequal strips, these reflexing to reveal the ripe berries; berries bright orange to red, globose, ca 0.5 cm diam., each with 1-3 seeds; seeds, ca 3mm diam., pace brown.
Steep to precipitous leaf litter-covered red clay-loam slopes beneath open to rather dense canopy of moist upper hill forest in light to moderate shade.

Native to:


Alocasia chaii P.C.Boyce appears in other Kew resources:

First published in Gard. Bull. Singapore 58: 142 (2007)

Accepted by

  • Govaerts, R.H.A. (2011). World checklist of selected plant families published update Facilitated by the Trustees of the Royal Botanic Gardens, Kew.


CATE Araceae

  • Boyce, P.C. 2007. Studies on the Alocasia Schott (Araceae-Colocasieae) of Borneo: I Two new species from Sarawak, Malaysian Borneo. Gardens' Bulletin Singapore, 58 (2), 141-154.

  • CATE Araceae

    Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.

  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at and
    © Copyright 2017 World Checklist of Selected Plant Families.

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at and
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.

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