Australian Tropical Rainforest Plants - Online edition

Lasjia whelanii (F.M.Bailey) P.H.Weston & A.R.Mast


Tree
Click/tap on images to enlarge
Flowers. © Barry Jago
Leaves and Flowers. © CSIRO
Leaves and fruit. © CSIRO
Fruit, front view, dehisced and seed. © W. T. Cooper
Scale bar 10mm. © CSIRO
1st leaf stage, cotyledons absent, hypogeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Mast, A.R., Willis, C.L., Jones, E.H., Downs, K.M. & Weston, P.H. (2008) American Journal of Botany 95(7): 865.

Common name

Whelan's Macadamia; Oak, Whelan's Silky; Oak, Silky; Whelan's Silky Oak; Silky Oak

Stem

Oak grain in the wood and a corresponding pattern in the inner blaze.

Leaves

Oak grain in the twigs. Usually 4 or 5 leaves in each whorl. Leaf blades about 6-21.5 x 2-6.5 cm. Lateral veins forming loops inside the blade margin.

Flowers

Flowers +/- paired, but lacking a common peduncle, pedicel longer than the corolla. Flower bracts not observed. Tepals +/- glabrous, about 2.5 mm long. Hypogynous glands fused to form a shallow, lobed cup at the base of the ovary. Ovary sessile, densely pubescent. Ovules 2.

Fruit

Fruits +/- globular, about 4-5 cm diam. Seed globular, about 3.5-4 cm diam. Endocarp + testa about 2.5-5 mm thick. Pericarp marked by rays of radial fibres and thickened cells in transverse section. Embryo +/- mushroom-shaped.

Seedlings

First few leaves not always in whorls, alternate. At the tenth leaf stage: leaf blade elongate-elliptic, apex acuminate, base cuneate, in whorls of three, upper surface +/- glabrous, a few hairs may be present on the midrib near the base; petiole and terminal bud clothed in reddish brown, prostrate hairs. Seed germination time 88 days.

Distribution and Ecology

Endemic to NEQ. Altitudinal range from sea level to 650 m. Grows in well developed lowland rain forest.

Natural History & Notes

The seeds of this species are strongly cyanogenetic and strong positive reactions to HCN have been obtained even after 11 years of storage. Everist (1974).

A large tree with a dense dark green growth and contrasting white flowers. It has potential for plants in parks in tropical areas.

Produces a useful timber with a conspicuous oak grain, suitable for construction work.

Wood specific gravity 1.00 Cause et al. (1989).

Synonyms
Macadamia whelanii (F.M.Bailey) F.M.Bailey, The Queensland Flora 4: 1330(1901). Helicia whelanii F.M.Bailey, Botany of the Bellenden Ker Expedition (in Meston: Report of the Government Scientific Expedition to Bellenden-Ker Range) : 55(1889), Type: Abundant along Tringilburra Creek and thence to Whelanian Pools. Helicia whelanii F.M.Bailey, Report on New Plants, Preliminary to General Report on Botanical Results on Mestons Expedition to the Bellenden-Ker Range : 2(1889), Type: Abundant along Tringilburra Creek and thence to Whelanian Pools.
RFK Code
476
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