Macaranga motleyana (Mull.Arg.) Mull.Arg., in DC. Prodr. 15, 2 (1866)
Named after J. Motley [?-1859], a British engineer who collected plants.
Macaranga motleyana subsp. motleyana
Mappa motleyana Müll.Arg.
Tanarius motleyanus (Müll.Arg.) Kuntze
Understorey tree up to 20 m tall and 16 cm dbh. Twigs hollow, ant-inhabited.
Stipules recurved and producing food bodies for the ants, ca. 8 mm long. Leaves
alternate, simple, 3-5-lobed, peltate, plamately veined, glabrous, glaucous
below. Flowers ca. 1 mm diameter, green-yellowish, placed in bundles within
bracts which are placed within a panicle. Fruits ca. 9 mm diameter,
green-white-bluish with yellow glandular ridges, 4-lobed, dehiscent capsules,
seeds with red aril.
Slender glaucous tree to 20 m tall with branches clustered towards the ends of the axes, flowering
from 4-5 m tall in open areas; twigs 6-9(-10) mm diameter, glabrous, rarely with some scattered
minute ferrugineus hairs towards the apex, densely glaucous, hollow, housing ants, usually exuding
some reddish clear latex when cut. Bark smooth, hoop marked, mottled pale grey-brown and white.
Stipules rather small, ovate, 4-7 by 6-7 mm, the pair not completely encircling the twig, recurved,
succulent, adaxial surface sometimes with scattered minute ferrugineus hairs when young, abaxial
surface producing food-bodies, 2-4 pairs present on the shoots but often caducous. Leaves: petioles
terete, slender, 10-20 cm long, glaucous, glabrous or sometimes with scattered minute ferrugineus
hairs; blades ovate, (15-)20-35 by (10-)12-25 cm, usually deeply trilobed, sometimes with an
additional pair of basal leaf cusps or lobes, dissected to 1/3-1/2 of the leaf length rarely less,
central lobe c. 4-8 cm wide usually quite narrow near the base, often with +/- parallel sides,
lateral lobes c. 3-7 cm wide ascending and remaining quite close to the main lobe with narrow
sinuses, 2-5(-6) cm peltate, base characteristically narrowly rounded, margin entire, apices
narrowing suddenly, shortly acuminate, adaxial surface glabrous, abaxial surface mostly glabrous but
usually with minute ferrugineus hairs on the veins, densely glaucous; 1st degree venation palmate
with 6-7(-8) prominent veins, 2nd degree venation scalariform, looping near the leaf margins and
terminating at the margin in tiny protruding conical nectaries, 3rd-4th degree venation only feintly
visible not prominently raised from the abaxial leaf surface; young leaves red-brown, minutely
ferrugineus pubescent on the adaxial surface and densely yellow granular glandular on the abaxial
surface, soon becoming glabrous. Staminate inflorescences paniculate, erect, 10-22(-25) by 10-18 cm,
basal axes mostly glabrous and densely glaucous, distal axes sparsely to densely ferrugineus
pubescent, up to 4 axis orders, main unbranched axis 2-8 cm long flattened, first pair of secondary
branches +/- opposite with accessory branches; bracts elliptic, 7-17 by 3-6 mm, usually persistent,
bright yellow-green when fresh and drying black, margin entire, apex acute, minutely ferrugineus
pubescent; flower clusters with c. 10 flowers, decussately arranged and strongly grouped on ultimate
inflorescence branches; bracteoles ovate to broadly ovate, 3-5 by 2.5-4 mm, enclosing flower
clusters, margin quite deeply and evenly pectinate with c. 14 equally spaced teeth, apex acute and
usually terminated by a narrowly caudate apex c. 1 mm long with a tiny conical nectary, both
surfaces scattered to densely covered with minute silvery to golden red-brown hairs and yellow
granular glands, adaxial surface with a dense patch of minute ferrugineus hairs at the base.
Staminate flowers c. 1 mm long, shortly pedicellate; sepals free, splitting irregularly to the base
at anthesis, apex usually scattered with minute red-brown hairs; stamens 2-3; anthers 4-locular.
Pistillate inflorescences paniculate, erect, 4-10 by 3-5(-6) cm, stout, covered in fine ferrugineus
hairs, fewer hairs and more glaucous towards the base, 2(-3) axis orders, secondary branches +/-
opposite without accessory branches; bracts caducous, not seen. Pistillate flowers c. 5-7 by 4-5 mm,
solitary in bract axils; calyx urceolate, 3-4 mm long, densely covered with fine ferrugineus hairs
and scattered yellow granular glands, persistent, splitting irregularly as ovary expands; ovary
4-5(-6)-carpellate, c. 3 mm long; styles c. 2-3 mm long, fused at base, free and spreading from
c. 1/2 of the length, persisting to form a prominent 3-5 mm long crown at the fruit apex; stigma not
dissected. Fruits subglobose, compressed, 7-9 by 9-13 mm, pedicellate, sutures bluish and glaucous,
one discrete glandular patch on each carpel wall developing into a slightly raised flat disc covered
in yellow, sticky exudate; pedicel 4-8 mm long, scattered with minute ferrugineus hairs, glaucous.
Seeds subtriangular-ovoid, 3.5-4 mm in diam., black, with shallow coarse grooves and a small
cruciform scar, encased in a fleshy bright red aril. [from Flora Malesiana]
In disturbed and open sites (gaps, riversides) in mixed dipterocarp and
keranga forests up to 700 m altitude. Also very common in secondary forests,
scrub, and roadsides, quite often in or near swampy areas. On sandy and
limestone soils, but also on ultrabasic.
Borneo: Asang rabata, Sedaman kubal.