Australian Tropical Rainforest Plants - Online edition

Calamus aruensis Becc.

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Female and sterile male flowers at anthesis [not vouchered]. © J.L. Dowe
Male flowers at anthesis [not vouchered]. © J.L. Dowe
Fruit [not vouchered]. © J.L. Dowe
In lowland rainforest habitat [not vouchered]. © J.L. Dowe
Stem and leaf base. © CSIRO
Scale bar 10mm. © CSIRO

Beccari, O. (1908) Annals Royal Botanic Gardens, Calcutta 11: 461. Type: O. Beccari, Jabu- Lengan (Aru Island), May 1873.

Common name

Lockerbie Scrub wait-a-while


Stems usually solitary, occasionally clustered. A slender vine not exceeding a stem diameter of 2 cm. Vine stem surface very smooth and glassy.


Leaflets 25-40 in each compound leaf, the leaflet bearing section up to 1.5 m long or longer with the compound leaf axis extending beyond the leaflet bearing section as a tendril 1.5 m long or longer, armed with recurved spines. Leaflet blades sessile, about 15-43 x 1.5-5.5 cm with fine hair-like teeth along the margin, venation longitudinal and parallel with 8-10 parallel veins. Leaflet blades corrugated in transverse section. Compound leaf axis armed with recurved spines on the underside, more numerous towards the apex. Sheathing petiole bases unarmed or only sparsely armed.


Inflorescence to 2.7 m long, branched. Staminate flowers 2-3.2 x 1-1.5 mm in bud, opening to 2-4 mm wide; sepals 1-1.2 mm long, 0.8-1 mm wide, basally connate, lobes triangular, light green, glabrous; petals 1.8-2 mm x 0.9-1 mm, light green; stamens 1.8-2 mm long, anthers; pistillode present. Pistillate flowers 2-2.7 x 1-1.2 mm, green glabrous. Sterile staminate flowers also present.


Infructescence large, about 2 m long. Individual fruits about 9-11 x 9-12 mm, clothed in overlapping diamond-shaped, shingle-like scales. Stalks about 2-2.5 mm long, perianth persistent at the base of the fruit. Seeds globular, about 7-8 mm diam. Embryo +/- clavate, about 2 mm long, located in a cavity just beneath the surface of the testa.


Features not available.

Distribution and Ecology

Occurs in CYP. Known only from a few collections, one from the Jardine River and the other two from the Lockerbie area. Altitudinal range probably quite small, from near sea level to 60 m. Grows in lowland rain forest or monsoon forest. Also widespread in New Guinea and the Solomon Islands.

Natural History & Notes

Distinguishing features: leaf terminating in a cirrus (whip-like extension armed with spines); stems clustered at base; leaf sheath unarmed or sparsely armed with spines in mature plants; leaf with 13-23 leaflets on each side of midrib.

Calamus hollrungii Becc., Fl. Kais. Wilh. Land : 17(1889), Type: German New Guinea, Augusta Station, Hollrung 667; holo: B?. Calamus latisectus Burret, Notizbl. Bot. Gart. Berlin-Dahlem 13: 319(1936), Type: Papua New Guinea, Malahang, Clemens 62; Holo:B; Iso L.
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