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Croton triacros

Family

Euphorbiaceae

Botanical Name

Croton triacros F.Muell.

Mueller, F.J.H. von (1868) Fragmenta Phytographiae Australiae 6: 185. Type: Ad sinum orarium Rockinghams Bay. Dallachy. Lecto: MEL231564 Fide Forster (2003).

Common name

SPEAR BIRCH; Birch, Spear; White Croton

Stem

Seldom exceeding 30 cm dbh. Blaze odour very spicy or peppery.

Leaves

Leaf blades about 6-13 x 3-8 cm. Oil dots visible with a lens and almost visible to the naked eye. Two raised glands on the underside of the leaf blade at the base where it joins the petiole. Old leaves turn orange prior to falling.

Flowers

Male flowers distributed from the base to the apex of each raceme with the female flowers usually near the base. Inflorescence and calyx sparsely clothed in stellate scales. Gland present at or near the base of each sepal. Petal and sepal apices and the centre of the flower densely clothed in tortuous long white hairs. Male flowers about 3 mm diam. with about ten stamens. Ovary in female flower clothed in stellate scales, one ovule per locule. Stigmas bilobed.

Fruit

Capsules about 6-8 mm diam., sparsely clothed in stellate scales. Styles and stigmas persistent, prostrate at the apex of the fruit. Outermost layer of the fruit breaks away from the pedicel and splits upwards. Aril is a caruncle. Cotyledons white or cream, much wider than the radicle.

Seedlings

Cotyledons +/- orbicular or elliptic, about 10-15 x 10-14 mm. Stellate hairs visible on the first pair of leaves, stems and petioles. At the tenth leaf stage: midrib on the underside of the leaf blade clothed in pale to rusty, stellate hairs or scales. Midrib raised on the upper surface of the leaf blade. Stipules small and inconspicuous. Terminal bud, stem and petiole clothed in pale to rusty, stellate hairs or scales.

Distribution and Ecology

Endemic to Queensland, occurs in CYP and NEQ. Altitudinal range from 600-1000 m. Grows in drier rain forest, often associated with Kauri Pine (Agathis robusta).

Natural History

Very similar to Croton brachypus and doubtfully distinct.

CYP

X

NEQ

X

Shrub (woody or herbaceous, 1-6 m tall)

X

Tree

X

RFK Code

431