Vitex rotundifolia

Family

Lamiaceae

Botanical Name

Vitex rotundifolia L.f.

Linnaeus, C. von filius (1782) Supplementum Plantarum: 294. Type: Japan, Thunberg s.n.; holo: LINN.

Synonyms

Vitex trifolia var. obovata Benth., Flora Australiensis 5: 67(1870), Type: Syn: QLD, Snapper Is., May 1819, A. Cunningham 217; syn: BM, K, MEL; NT, Goulburn & Sims Is., 1818, A. Cunningham 216; syn: BM, K, MEL. Vitex trifolia var. simplicifolia Cham., Linnaea 7: 107(1832), Type: Philippines, Cavite, Luzon, Collector unknown; holo: B (destroyed?). Vitex trifolia var. unifoliolata Schauer, Prodromus 11: 683(1847), Type: Syn: Mauritius, Sieber; G-DC; Philippines, Chamisso; B (destroyed?); China, various collectors; Japan, Thunberg & Goering; Australia, R. Brown; BM.

Common name

Roundleaf Chastetree

Stem

Usually grows as a trailing vine over the surface of the sand but also flowers and fruits as a shrub 1-3 m tall.

Leaves

Leaf blades small, about 1.7-4.5 x 0.8-3 cm, petioles about 0.5 cm long. Twigs, petioles and both the upper and lower surfaces of the leaf blade clothed in pale velvety hairs. Lateral veins about 5-9 on each side of the midrib, difficult to discern on either the upper or lower leaf blade surfaces.

Flowers

Inflorescence about 3-13 cm long, pedicels densely glandular and tomentulose, about 0.5-2 mm long. Calyx cyathiform, glandular and silky-tomentulose outside, glabrous on the inner surface, shortly 5-toothed at the apex. Tube cylindrical, about 3-4.5 x 2-3 mm. Corolla tubular in the lower half, tube about 6-9 mm long, but 2-lipped and 5-lobed at the apex, glandular and silky-tomentulose on the outer surface, villous on the inner surface of the tube, the lateral lobes shorter. Stamens four, exserted, filaments about 3.6-8 mm long. Anthers about 1-2 mm long. Ovary densely glandular, about 1-1.5 mm diam., style exserted, glabrous, about 8-13 mm long, bifid at the apex.

Fruit

Fruits globose, about 4-5.5 x 5-6.5 mm, clothed in small globular glands. Calyx about 5-6.5 mm long, persistent at the base. Cotyledons about twice as wide as the radicle.

Seedlings

Features not available.

Distribution and Ecology

Occurs in WA, NT, CYP, NEQ and southwards as far as south-eastern Queensland. Altitudinal range very small being found on beaches just above the high water mark. Usually grows in strand vegetation but sometimes found in beach forest, monsoon forest and vine thickets. Also occurs in Asia, Malesia, New Caledonia and other Pacific islands.