Causonis japonica (Thunb.) Raf.

Rafinesque, C.S. (1838) Sylva Tellur. 87.

Bushkiller

Vine stem diameters to 4 cm recorded. Outer blaze greenish. Stems laterally flattened. Cut stems produce a sticky exudate.

Leaves pedately compound with five leaflets. Leaflet blades about 3-9 x 1.5-4.5 cm, middle leaflets larger than the lateral leaflets, lateral leaflet stalks about 0.4-0.5 cm long. Stalk of the middle leaflet about 2-2.2 cm long. Leaflet blades usually hairy on both the upper and lower surfaces, margins coarsely serrate with 2-12 teeth on each side. Lateral veins about 5-9 on each side of the midrib. Stipules hairy, broadly triangular, about 2.5-5 mm long. Tendrils usually branched, leaf-opposed.

Pedicels clothed in short fleshy hairs. Calyx lobes scarcely discernible. Flowers about 6 mm diam. Petals about 2.5 x 2 mm, thickened towards the apex and with short fleshy hairs on the outer surface. Staminal filaments about 1 mm long. Ovary surrounded by a large flat 4-lobed disk with fleshy hairs on the surface.

Fruits globular to depressed globular, about 6-12 mm diam., apex shortly pointed, perianth persistent at the base. Seeds 1-4 per fruit. Seeds variable in shape, mostly angled and obovoid or heart-shaped. Seeds about 3.5-5 x 3.5 mm. Testa sculptured with a couple of pits on each side. Embryo about 1 mm long.

Cotyledons about 15 x 10 mm, petioles about 4-5 mm long. First leaf compound, leaflets 3, margins toothed. At the tenth leaf stage: leaf compound, pedate with 5 leaflets. Middle leaflet blade about 5 x 2 cm, stalk about 0.8 cm long. Lateral leaf blades about 3-4 x 1.5 cm, bases oblique, stalks about 0.2-0.3 cm long. Stipules broadly triangular, about 1.5 mm long. Seed germination time 133 days.

Occurs in CYP, NEQ, CEQ and southwards to south eastern Queensland. Altitudinal range in CYP and NEQ from near sea level to 1100 m. Grows in disturbed areas in lowland and upland rain forest. Also occurs in Asia as far north as Korea, Malesia and the Pacific islands eastwards as far as New Caledonia.

Cayratia japonica (Thunb.) Gagnep., Notulae Systematicae (Paris) 1 : 349 (1911).  Columella japonica (Thunb.) Merrill, Philippine Journal of Science. Section C, Botany (1918): 145 (1918). Cissus japonica Willd., Species Plantarum ed. 4, 1(2) : 659(1798), Type: Habitat in Japonica. Vitis japonica Thunb., Flora Japonica : 104 (1784), Type: Crescit circum Nagasaki, inque Papenberg. Cissus obovata M.A.Lawson, Fl. Brit. India 1: 658 (1875), Type: Khasia Mts, alt. 3-4000 ft, H. f. & T. Vitis mollis Wall., Numer. List (1831-32), Type: Wall. Cat. No. 6025; holo: K?.