Xenostegia tridentata (L.) D.F.Austin & Staples

Austin, D.F. & Staples, G.W. (1981) Brittonia 32: 533.

Vine, African Morning; African Morning Vine

A slender vine not exceeding a stem diameter of 2 cm.

Leaf blades about 12-55 x 3-12 mm, petioles absent or about 0.5-1 mm long. Leaf blade margins with 2-5 teeth on each side but only near the base of the leaf blade. Lateral veins difficult to discern.

Peduncles slender, about 30-40 mm long. Pedicels about 8-10 mm long. Sepals glabrous, ovate or narrowly ovate, about 4-6 x 2 mm. Corolla trumpet-shaped, about 8-12 x 7-12 mm. Stamens about 5 mm long. Ovary globose, about 0.6-0.7 mm diam. Style about 5-5.5 mm long. Stigmas 2, globose, surface papillose. Ovules 2 per locule.

Fruits globose, about 5 x 5-7 mm, enveloped by the persistent sepals. Seeds up to 4 per fruit, each seed angular, about 4 x 3 mm, shaped like an orange segment. Cotyledons bilobed, crumpled and folded in a complex fashion with lenses of endosperm between the folds. Radicle curved, about 2-6 mm long.

Cotyledons glabrous, bilobed, about 30 mm long, each lobe about 1.5 mm wide. First leaves very narrowly elliptic-lanceolate, apex acute, base cordate with 1 or 2 teeth on each side. Petioles short, less than 1 mm long. Hypocotyl papillose. At the tenth leaf stage: leaf blade linear-lanceolate, apex acuminate, base +/- sagittate. Margin entire except for 4-6 small teeth on the lobes at the base. Lower surface of the leaf blade papillose, upper surface clothed in fine translucent hairs. Oil dots not very obvious, more readily seen from below. Leaf, stem and petiole exudate clear. Seed germination time 78 days.

Occurs in WA, NT, CYP, NEQ, CEQ and southwards almost as far as south-eastern Queensland. Altitudinal range from near sea level to 550 m. Usually grows in open forest sometimes in riparian forest, beach forest or vine thicket. Also occurs in Asia and Malesia.