Australian Tropical Rainforest Plants - Online edition

Helicia australasica F.Muell.


Shrub (woody or herbaceous, 1-6 m tall)
Tree
Click/tap on images to enlarge
Flowers. © G. Sankowsky
Inflorescence, buds. © G. Sankowsky
Leaves and Flowers. © CSIRO
Fruit. CC-BY J.L. Dowe
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Mueller, F.J.H. von in Hooker, W.J. (1857) Hooker's Journal of Botany & Kew Garden Miscellany 9 : 22. Type: Ad rivulorum ripas in vicinitate montium MAdams Range, 3 Oct. 1855, F. Mueller; holo: K.

Common name

Austral Oak; Creek Silky Oak; Oak, Creek Silky

Stem

Seldom exceeding 30 cm dbh. Oak grain in the wood and a corresponding red or dark brown pattern in the blaze.

Leaves

Oak grain in the twigs. Leaf blades about 6-23 x 4-8.5 cm. Petioles swollen at their junction with the twig. Lateral veins forming loops well inside the blade margin.

Flowers

Tepals about 8-15 mm long, ferruginous-pilose. Ovary ferruginous-tomentose. Ovules 2.

Fruit

Fruits ovoid, about 8-11 x 5-7.5 mm. Seed ovoid, about 6-8 x 4-5 mm.

Seedlings

Cotyledons fleshy, without venation. First pair of leaves ovate, margins dentate or serrate, glabrous on the upper surface. At the tenth leaf stage: leaf blade obovate, apex acute, base attenuate, margin of leaf blade irregular, dentate to serrate, glabrous on the upper surface or with a few scattered hairs along the midrib, midrib raised on the upper surface. Stem clothed in prostrate brown hairs. Seed germination time 12 to 115 days.

Distribution and Ecology

Occurs in NT, CYP and NEQ. Altitudinal range from sea level to 1100 m. Grows as an understory tree in monsoon forest, dry rain forest and well developed rain forest. Also occurs in New Guinea.

Natural History & Notes

Not commonly cultivated as yet, however, it does have potential because of the profuse flowering that sometimes occurs.

Synonyms
Helicia glabrescens C.T.White, Proceedings of the Royal Society of Queensland 55: 81(1944), Type: Cook District: Barron River, E. Cowley 74B (type: Flowers), Sept. 1892 (large shrub). Helicia dentellata Sleumer, Bot. Jahrb. Syst. 70: 147(1939), Type: Lake Daviumbu, Middle Fly River, Sept. 1936, L. J. Brass 7917; iso: BRI.
RFK Code
307
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