Large, woody or rarely herbaceous, dioecious vines; tendrils leaf-opposed,
simple or branched. Leaves 3-7 -foliolate, digitate or pedate, petiolate, hairy
to glabrous; leaflets petiolulate to subsessile. Inflorescence axillary; cymes,
pedunculate. Flowers unisexual. Calyx cupular or saucer-shaped, truncate
or obscurely 4-lobed. Petals 4, free, usually hooded and sometimes with a
dorsal spur at apex. Stamens 4; filaments short; anthers oblong-oval. Disc
usually distinct, 4-lobed. Style short, thick or simulating ovary; stigma broad,
usually 4-lobed. Berries globose or ellipsoid, usually succulent, 1-4 -seeded.
Seeds obovate to elliptic-oblong; adaxial surface with a linear filiform raphe;
abaxial surface with a linear, spathulate or orbicular chalazal knot; endosperm
T-shaped in cross section.
Chiefly distributed in South-east Asia and Indo-Malesia, one species
in Australia; ca 95 species, 16 in India.
Notes.
Tetrastigma shares the character of 4-merous flowers with Cissus,
Cayratia and Cyphostemma, but in all these genera the flowers are bisexual
and the stigma simple or slightly 2-fid.
KEY TO THE SPECIES
| 1a. Leaves digitately 3-6 -foliolate
|
2
|
| b. Leaves pedately 3-7-foliolate
|
8
|
| 2a. Petals of at least male flowers with a dorsal spur
|
3
|
| b. Petals without dorsal spur
|
4
|
| 3a. Petals ca 2.5 mm long; ovary pubescent; berries ellipsoid.
1.5-2.5 cm across; seeds 11-14 x 9-10 mm; leaves 3-5 -foliolate
|
11.
Tetrastigma obovatum
|
| b. Petals ca 1 mm long; ovary glabrous; berries globose. 6-9 mm
across; seeds ca 6 x 5 mm; leaves 3-foliolate
|
4.
Tetrastigma bracteolatum
|
| b. Flowers not rusty pubescent; berries globose; seeds globose
to oblong·ovoid, less than 10 mm long
|
5
|
| b. Berries less than 1 cm across; seeds 6-7 x 5 mm
|
6
|
| 6a. Leaves 5-foliolate; leaflets subsessile with cuspidate-serrate
margins; calyx ciliate at margin
|
12.
Tetrastigma obtectum
|
| b. Leaves 3-foliolate; leaflets petiolulate with obscurely serrate-dentate
to subentire margins; calyx not ciliate at margin
|
7
|
| 7a. Leaflets elliptic-obovate; petiolules of terminal leaflets
1.5-2.5 cm long; ovary glabrous; berries 1-seeded.
|
7.
Tetrastigma gamblei
|
| b. Leaflets elliptic-lanceolate; petiolules of terminal leaflets
ca 7 mm long; ovary pubescent; berries 2-4-seeded
|
3.
Tetrastigma angustifolium
|
| 8a. Berries more than 2 cm across; seeds 11-12 x 5-7 mm
|
9
|
| b. Berries less than 1 cm across; seeds 5-10 x 3.5-6 mm
|
10
|
| 9a. Branchlets muricate; venation between secondary veins of
leaflets prominent
|
16.
Tetrastigma sulcatum
|
| b. Branchlets smooth; venation between secondary veins of
leaflets obscure
|
8.
Tetrastigma hookeri
|
| 10a. Berries turbinate-globose; seeds triangular-obcordate, adaxial surface with a prominent central longitudinal ridge
|
14.
Tetrastigma rumicispermum
|
| b. Berries globose or ovoid; seeds obovoid, oblong-ovoid to
oblong-ellipsoid or pyriform, adaxial surface without a central ridge
|
11
|
| b. Branchlets smooth; leaflets not revolute at margins
|
12
|
| b. Style indistinct or absent; stigma 4-lobed
|
13
|
| 13a. Robust climbers; branches thick; tendrils simple; terminal leaflets 11-20 x 3.5-10 cm; lateral leaflets 7-16 x 3-8 cm; seeds 6-10 x 4-6 mm
|
14
|
| b. Weak climbers; branches slender; tendrils bifurcate or branched; terminal leaflets 3-10 (-12) x 1.5-3 (-4) cm; lateral leaflets 1.5-6 (-7) x 0.8-2(-3)cm; seeds ca 5 x 3-4 mm
|
15
|
| 15a. Petals with a prominent dorsal spur; seeds with two parallel
longitudinal ridges and a shallow groove on abaxial surface,
corrugate on sides
|
1.
Tetrastigma affine
|
| b. Petals without dorsal spur; seeds without ridges on abaxial
surface, not corrugate on sides
|
15.
Tetrastigma serrulatum
|
