Australian Tropical Rainforest Plants - Online edition

Strychnos psilosperma F.Muell.

Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Flowers [not vouchered]. © G. Sankowsky
Leaves and fruits. © CSIRO
Scale bar 10mm. © CSIRO
Cotyledon and 10th leaf stage, epigeal germination. © CSIRO
Cotyledon and 10th leaf stage, epigeal germination. © CSIRO

Mueller, F.J.H. von (1864) Fragmenta Phytographiae Australiae 4: 44. Type: Ad montem Archer et montem Elliot in locis silvarum umbrosissimis. Fitzalan et Dallachy.

Common name

Threadwood; Threadwood Boxwood; Boxwood, Threaded; Strychnine Tree; Sagowood; Strychnine Bush


Seldom exceeding 30 cm dbh. Living bark layer quite thin.


Leaf blades about 3.9-6.5 x 2.4-5.2 cm, variable in shape but always three or 5-veined. Midrib often projecting from the apex of the leaf blade as a short, needle-like tip. Midrib flush with the upper surface. Pale, circular lenticels usually visible on the twigs.


Calyx about 1-2 mm long. Corolla about 3-4 mm long, tube about as long as the lobes. Stamens inserted below the ring of hairs, filaments shortly glabrous. Anthers about 0.7-1 mm long. Ovary about 1.2-2 mm long, glabrous.


Fruits obliquely ovoid to globular, about 8-15 x 7-15 mm. Seeds about 6-10 x 6-10 mm.


Cotyledons ovate to orbicular, about 12-17 x 12-18 mm with a few hairs on the upper surface along the venation and margin. Usually one pair of cataphylls produced before the first pair of true leaves. First pair of true leaf blades ovate, much smaller than the cotyledons, each with a spine about 8 mm long in the axil. At the tenth leaf stage: leaf blade ovate, about 3-5 mm long, apex acute, acuminate or shortly aristate, sharp, base rounded, obtuse, glabrous on the upper surface, each leaf with a simple, up to 1 cm long, axillary spine. Petioles and stems densely clothed in short looping or arched hairs. Seed germination time 119 to 144 days.

Distribution and Ecology

Occurs in CYP, NEQ, CEQ and southwards to south eastern Queensland. Altitudinal range from 300-1000 m. Grows in monsoon forest and drier rain forest on a variety of sites. Also occurs in SE Asia and Malesia.

Natural History & Notes

Although this species is suspected of being poisonous to stock there is little or no evidence to substantiate the claim. Everist (1974).

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