Australian Tropical Rainforest Plants - Online edition

Tristaniopsis exiliflora (F.Muell.) Peter G.Wilson & J.T.Waterh.

Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Flower and buds. © Barry Jago
Flowers. © G. Sankowsky
Leaves and flowers. © G. Sankowsky
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO

Wilson, Peter G. & Waterhouse, J.T. (1982) Australian Journal of Botany 30: 434.

Common name

Kanuka box; Kanuka; River Gum; Box, Kanuka; Watergum


Often a poorly formed tree. Bark shed in long strips, the edges of which curl to form cylinders.


Leaf blades about 7.5-11 x 1.5-2.2 cm, much paler on the underside. Midrib depressed on the upper surface.


Inflorescence shorter than the leaves, about 30 flowers per inflorescence. Calyx pubescent, lobes small, about 0.5-1 mm long. Petals about 1.5 mm long. Stamens fused into fascicles opposite the petals, stamens 3-4(-6) per fascicle, fascicles shorter than the petals. Ovary apex pubescent. Style about 1.5 mm long.


Fruits small, splitting to the base at maturity, up to 7 mm diam. when fully open, about 2.5-3 mm diam. before opening, calyx persistent at the base. Seeds small, about 1.5-2 x 1.5 mm, wingless. Cotyledons contortuplicate.


Cotyledons wider than long, bilobed, about 2-3 x 4-6 mm, apex broadly emarginate, base cordate or truncate. Oil dots very small, visible only with a lens. At the tenth leaf stage: leaf blade obovate or narrowly obovate, apex acute, base attenuate, glabrous; oil dots numerous, small, visible with a lens or just visible to the naked eye. Seed germination time 7 to 18 days.

Distribution and Ecology

Endemic to Queensland, occurs in CYP and NEQ. Altitudinal range from 50-1000 m. Grows as a rheophyte along creeks and watercourses.

Tristania exiliflora F.Muell., Fragm. 5: 11(1865), Type: Queensland, Rockingham Bay, J. Dallachy, (BM (?), UC.
RFK Code
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