Family:
Araceae Juss.

Homalomena giamensis L.S.Tung, S.Y.Wong & P.C.Boyce

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

[CATE]

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Distribution

Malaysian Borneo: Sarawak, Kuching Division, Siburan, endemic to karst limestone in the vicinity of Kampung Giam.

Ecology

Terrestrial in deep leaf litter over limestone-derived loams on ridges and moderate slopes beneath lowland perhumid evergreen broadleaf forest on and adjacent to karst limestone. 35-50 masl.

General Description

Medium, somewhat robust, strongly aromatic (camphor) evergreen glabrous mesophytic herbs to ca. 1 m tall. Stem pleionanthic, erect to ascending, ca. 3 cm thick, medium green, internodes to ca. 1 cm long. Leaves up to ca. 15 together, ca. 6 per module; modules starting with a conspicuous 2-keeled short-duration prophyll to 30 cm long, medium-green, glossy; petiole erect, 40-45 cm long, sub-terete except for the distal-most portion where very shallowly dorsally channeled with rounded margins, obscurely pulvinate ca. 2/3 along length, pulvinus ca. 4 cm long, petiole bases clasping, petiole bright green with obscure longitudinal darker green striae; petiolar sheath ca. 6-10 cm long, ca. 1/3 of petiole length, equal, persistent, decurrent at apex, margin erect, pale glossy green; lamina rather broadly ovato-sagittate, 18-30 cm long X 14-25 cm wide, rubbery-leathery and somewhat quilted between the primary and interprimary veins, glossy bright green adaxially, paler green abaxially, base cordate to sagittato-cordate, tip acute, acuminate for ca. 2 cm thence tubular-apiculate for ca. 2-3 mm; posterior lobes short, straight, ovate to ovato-triangular, sinus rather narrow, lobes 6-9 cm long; midrib raised abaxially green when fresh, adaxially sunken slightly into lamina, ca. 3 mm wide, with ca. 9-11 primary lateral veins on each side, diverging at 30°-80° from the midrib, adaxially impressed abaxially slightly raised, distal-most veins curved slightly towards the apex when near the margin, interprimary veins barely distinguished from the primary lateral veins, alternating irregularly with primaries; secondary venation obscure, running parallel to the interprimary veins, striate; tertiary venation not visible; all veins running into a slightly thickened intermarginal vein. Inflorescences up to 5 together, erect and smelling powerfully of anethol (anise) at anthesis, thence declinate, subtending prophyll, short, usually less than 5 cm long; peduncle to ca. 25 cm long x ca. 5 mm diam. at the spathe insertion, glossy pale green. Spathe ca. 9-11 cm long, tightly furled prior to anthesis, lower spathe inflating at pistillate anthesis and the margins gaping to partially reveal spadix, margins also recurving, spathe limb loosening at pistillate anthesis, thence inflating and then opening wide, spathe interior white at anthesis, exterior pale glossy green with numerous faint longitudinal striae; spathe fully closing post anthesis, and then turning pale green and eventually dark green; lower spathe ovoid-ellipsoid, twice as long at spathe limb, ca. 6-7 cm long, moderately constricted at the junction of the spathe limb, the constriction coinciding with junction of the staminate and pistillate flower zones; spathe limb ovato-triangular, ca. 3-4 cm long x ca. 3.5 cm wide (at staminate anthesis), limb margins very slightly recurving at staminate anthesis, apex stiffly mucronate to ca. 4 mm long. Spadix exceeding the spathe by rapid spadix extension at anthesis onset, ca. 10.5 cm long, briefly stipitate; spadix contracting post anthesis and entirely enclosed in persistent spathe throughout the fruiting period; stipe ca. 3 mm long x 2 mm diam., weakly gibbose-cylindrical, and inserted slightly obliquely on peduncle, glossy white; pistiUateflower zone ca. 3.75 cm long X ca. 1 cm wide, slightly less than ca. 1/3 length of spadix, weakly fusiform; pistils ca. 2 mm x 1 mm, rather densely arranged, stoutly globose-cylindrical, somewhat trapezoidal-compressed where pressed against adjacent pistils, very pale yellow-white, each pistil associated with a ventrally located large staminode; style barely differentiated; stigma globose-capitate, smaller than ovary diam., pale gray; interpistillar staminodes stoutly abruptly globose-clavate on a slender stipe, clavate portion ca. 0.5 mm diam., slightly overtopping the associated pistil, waxy white; suprapistillar interstice zone absent; staminate flower zone to ca. 6 cm long, ca. 2/3 length of spadix, lowest portion composed of a few sterile staminate flowers, fertile portion producing large numerous amber-colored resin droplets during late pistillate and at onset of staminate anthesis, these particularly towards the spadix tip, from where they flow down the spadix, mixing with the pollen strands; staminate flowers well defined from one another, ca. 2.5 mm x 1 mm trapezoid, comprising 3-5 truncate stamens, each overtopped by a large, flat synconnective, anthers marginal with pollen extruded in strings and exiting via a notch in the synconnective margin, waxy white. Infructescence declinate to pendent, spathe entirely persistent, ca. 14 x 2 cm, the lower part weakly fusiform, deep glossy green, peduncle with darker green, short striae. Fruits & seeds not observed.

Native to:

Borneo

Homalomena giamensis L.S.Tung, S.Y.Wong & P.C.Boyce appears in other Kew resources:

First published in Aroideana 33: 203 (2010)

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

    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.
    http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0