Vitex acuminata

Family

Lamiaceae

Botanical Name

Vitex acuminata R.Br.

Brown, R. (1810) Prodromus Florae Novae Hollandiae: 512. Type: North Coast (possibly Cape York Peninsula), R. Brown s.n., 1802 - 1805; lecto: BM (J. J. Bennett 2320; iso: CANB, K.

Common name

Black Plum; Scrub Vitex; Vitex; Plum, Black

Stem

Blaze darkening on exposure. Dead bark layered.

Leaves

Terminal buds clothed in very short, prostrate, pale brown hairs. Leaflet blades about 5-10 x 3-5 cm. Midrib depressed on the upper surface. Domatia, if present, are tufts of pale coloured hairs.

Flowers

Inflorescence about 6-15 cm long, pedicels pubescent, 1-2 mm long. Calyx tubular, +/- cylindrical, minutely 5-toothed at the apex, pubescent and sparsely glandular outside, glabrous within, about 2-3 x 1.5-3 mm. Calyx lobes about 0.5 mm long. Corolla mauve, tubular, but 5-lobed in the upper half, pubescent and glandular outside, villous inside the tube with the hairs extending to the large, anterior lobe of the lower lip. Corolla lobes variable in size and shape, about 2.5-5 mm long. Corolla tube cylindrical, gradually dilated upwards, about twice as long as the calyx, about 5-7 x 3-4.5 mm at the apex. Stamens exserted, filaments attached to the middle of the corolla tube. Staminal filaments villous in the lower half, about 6-8 mm long, anther locules free and divaricate in the lower half, +/- horseshoe-shaped. Ovary globular, glabrous, without glands, about 1-1.5 mm diam. Style exserted, glabrous, filiform, about 8-11 mm long, stigmas bifid.

Fruit

Fruits globular-ellipsoid or somewhat obovoid, glabrous, about 4.5-14 x 3-8 mm, calyx accrescent, persistent at the base. Seed enclosed in a stone to about 7-10 x 5-6 mm, seeds to about 4-5.5 x 2 mm. Embryo about 5-6 mm long, cotyledons about 4-5 mm long, much wider than the radicle. Radicle about 1 mm long.

Seedlings

Cotyledons ovate or oblong, about 7-15 x 6-7 mm. First pair of leaves ovate or elliptic, margin toothed. At the tenth leaf stage: leaves +/- ovate, apex acuminate, base cuneate, small yellowish glands visible with a lens on both the upper and lower surfaces; midrib raised on the upper surface of the leaf blade; terminal bud and young shoot clothed in short, pale hairs.

Distribution and Ecology

Endemic to Australia, occurs in WA, NT, CYP and NEQ. Altitudinal range from sea level to 550 m. Grows in monsoon forest, beach forest and gallery forest.