Australian Tropical Rainforest Plants - Online edition

Rhodamnia spongiosa (F.M.Bailey) Domin

Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Flowers. CC-BY J.L. Dowe
Cauliflorous fruit. © B. Gray
Fruit, three views and cross section. © W. T. Cooper
Scale bar 10mm. © CSIRO
10th leaf stage. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO

Domin, K. (1928) Bibliotheca Botanica 89(4): 1030.

Common name

Northern Malletwood; Rhodamnia


Living bark layer very thin.


Leaf blades about 5.5-12 x 2.5-4.5 cm. Midrib and 2 main lateral veins depressed on the upper surface at least towards the base. Bark on the older twigs pale, spongy and somewhat papery, resembling that of Melaleuca spp. Petiole grooved on the upper surface. Terminal buds and young shoots clothed in pale brown, prostrate hairs.


Inflorescence usually on the twigs below or back from the leaves, shorter than the leaves. Calyx lobes about 2 mm long, pubescent on the outer and inner surfaces. Petals +/- obovate, about 7-8 mm long, pubescent on the outer surface, but glabrous on the inner surface.


Infructescence usually produced on the twigs below or back from the leaves, shorter than the leaves. Calyx lobes persistent at the apex. Fruits depressed globular, about 10 x 12-13 mm, surface clothed in white hairs. Seeds variable in shape, about 3-3.5 x 2-2.5 mm. Cotyledons small, just visible with a lens and narrower than the radicle.


Cotyledons ovate, about 5-7 mm long, apex acute or apiculate, base obtuse. Oil dots small, just visible with a lens. At the tenth leaf stage: leaf blade elliptic, apex acuminate, base cuneate or attenuate, upper surface with a few scattered hairs along midrib and main lateral veins, underside with short, almost matted, pale hairs; oil dots very small, numerous, visible with a lens; leaf blade strongly 3-veined; petiole, stem and terminal bud clothed in pale hairs. Petiole shallowly grooved on the upper surface. Seed germination time 8 to 58 days.

Distribution and Ecology

Occurs in CYP, NEQ, CEQ and southwards in southern central Queensland. Altitudinal range from near sea level to 1150 m. Grows as an understory tree in well developed rain forest on a variety of sites but more frequently encountered in drier rain forest often associated with Kauri Pine (Agathis robusta). Also occurs in New Guinea.

Rhodamnia trinervia var. spongiosa F.M.Bailey, Queensland Department of Agriculture and Stock. Botany Bulletin 7: 62(1893), Type: Tringilburra Creek, Bellenden-Ker Expedition. Barron River, E. Cowley.
RFK Code
Copyright © CSIRO 2020, all rights reserved.