pronounced: GROO-ee-uh oss-TRAH-liss
Grewia is named for Nehemiah Grew (1641–1712), English philosopher, physician and botanist. In 1682 he published his great work, The Anatomy of Plants. It was divided into 4 books, Anatomy of Vegetables begun, Anatomy of Roots, Anatomy of Trunks, and Anatomy of Leaves, Flowers, Fruits and Seeds. The book was illustrated with 82 plates. Linnaeus thought highly of his work, and named this genus in his honour. Australis is Latin for ‘south’.
The plant was first collected at Mackay, Queensland, in 1899. It is thought to be endemic to Queensland, and occurs in the north-east of the state and southwards along the coastal strip to central Queensland. It grows at altitudes from sea level up to about 600 m, and is found in monsoonal forests and vine thickets. The Townsville Branch of the Society for Growing Australian Plants records it growing by the Bald Rock Trail in the Town Common Conservation Park, and Valry Ryland records it on Magnetic Island on the ridge above Rocky Bay, and in the scrub below Nobby Head in Picnic Bay.
The plant is similar to Grewia retusifolia (Dog’s Balls), but tends to be taller (up to 3 or 4 m in height); the leaves are not as white on the lower surface, and the flowers have more stamens (up to about 40).
The leaves are two-ranked, with the blades lanceolate to narrow-ovate, up to about 12 cm long by 5 cm broad, with petioles 5-12 mm long. The upper surface of the leaves is covered with simple hairs, and the lower surface with both stellate and simple hairs, although sometimes the lower surface lacks hairs. The margins are serrate. The stipules are narrowly triangular, about 2 mm long. The bark of the twigs, when stripped, is strong and fibrous.
The flowers are almost 2 cm in diameter; the sepals are green outside but white within, a little over 1 cm long, the outer surface hairy and the inner glabrous. There are many stamens.
The fruits are globular and two-lobed, almost 1 cm in diameter, with a hairy surface. There are usually 4 seeds per fruit, each enclosed in a hard endocarp. The seeds are flattened, 4–6 mm long.