Sauropus Blume

Shrubs, undershrubs or herbs, very occasionally scandent or climbing, monoecious, glabrous or rarely pubescent. Leaves usually arising on lateral branchlets, alternate, entire and often reflexed along margins, penninerved or occasionally strongly 3-nerved at base; petioles short; stipules subpersistent. Inflorescences axillary, fasciculate or sometimes borne on densely bracteate brachyblasts, often bisexual, few-flowered, the females usually on the upper axils and solitary or in pairs, the males mostly maturing singly per axil. Male flowers: pedicellate; calyx unlobed and almost entire or variously lobed (lobes 3 + 3, imbricating), cupular or obconic, concave-cupular or globose in outline or flattened and discoid or star-shaped or very rarely reflexed forming an inverted urceolate-campanulate tube, the tips of the lobes inflexed; petals absent; disc absent; stamens 3, opposite the outer perianth segments; filaments connate into a minute or short column; anthers borne either horizontally at the corners of the common triangular connective and facing downwards, or vertically at the free apices of the filaments or sometimes connate into a mass. Female flowers: pedicellate; calyx segments 3 + 3, shortly connate, the outer usually larger than the inner, often accrescent in fruit; petals and disc absent; ovary 3- locular; locules biovulate; styles short, broad, mostly bifid and horizontal, rarely erect. Fruits capsular, occasionally somewhat fleshy, thin-walled, rarely shortly stipitate; seeds triquetrous, without arils.

Africa (Mauritius), India, Sri Lanka, Nepal, Bhutan, Bangladesh, Myanmar, China, Vietnam, Thailand to Malesia, extending to Australia, about 80 species; 12 species in India.

Literature. CHAKRABARTY, T. & M. GANGOPADHYAY (1996). The genus Sauropus Blume (Euphorbiaceae) in the Indian subcontinent. J. Econ. Taxon. Bot. 20(3): 513 - 545, ff. 1- 13.

Notes. The chromosome number reports so far are only for two species, S. bacciformis having n = 24 (Miller & Webster, Brittonia 14: 174 - 180. 1962; Datta, Taxon 16: 341 - 350. 1967) and S. androgynus with 2n = 50 (Sampath Kumar & Navaneetham, Proc. 68th Indian Sci. Congress, Part 3, p. 78. 1981) as well as 2n = 52 (Kothari et al., Taxon 29: 703 - 730. 1980).

Pollen grains of 3 species were studied by Punt (Wentia 7: 1 - 116. 1962). The grains are stephanocolporate, oblate, oblate-spheroidal or subprolate, intectate or tectate, reticulate or not.

KEY TO THE SPECIES

1 a. Leaves strongly trinerved at base

2

b. Leaves penninerved

3

2 a. Male perianth 2.5 - 5 mm in diam., discoid, unlobed, repand along margins

8. Sauropus repandus

b. Male perianth 4 - 10 mm in diam., star-shaped, deeply 6-lobed

12. Sauropus trinervis

3 a. Male flowers flattened

4

b. Male flowers not flattened

11

4 a. Male calyx discoid, entire or almost so

5

b. Male calyx star-shaped, lobed

6

5 a. Fruiting calyx up to 8 mm in diam.

1. Sauropus androgynus

b. Fruiting calyx 20 - 30 mm in diam.

9. Sauropus rhamnoides

6 a. Branchlets, petioles and leaves beneath puberulous

7

b. Branchlets, petioles and leaves beneath glabrous

8

7 a. Lateral nerves of leaves 7 - 8 pairs; male pedicels 8 - 10 mm long; calyx segments unlobed

3. Sauropus bishnupadae

b. Lateral nerves of leaves 3 - 6 pairs; male pedicels 2 - 6 mm long; calyx segments emarginate to deeply bilobulate

4. Sauropus compressus

8 a. Leaves 9 - 22 x 3 - 7.5 cm; petioles 4 - 6 mm long; female pedicels 5 - 20 mm long; fruits 10- 12 x 18 - 20 mm; fruiting pedicels 15 - 60 mm long

6. Sauropus macranthus

b. Leaves 0.5 - 5 x 0.1 - 3 cm; petioles 0.2 - 3 mm long; female pedicels 0.5 - 3 mm long; fruits 3 - 6 x 3.5 - 8 mm; fruiting pedicels up to 5 mm long

9

9 a. Segments of male calyx unlobed, entire

7. Sauropus quadrangularis

b. Segments of male calyx emarginate to deeply bilobulate

10

10 a. Petioles up to 0.6 mm long; male calyx 1 - 1.5 mm in diam.

2. Sauropus bacciformis

b. Petioles 1- 1.5 (- 2.5) mm long; male calyx 2 - 3.5 mm in diam.

4. Sauropus compressus

11 a. Male calyx unlobed or almost so, subglobose; fruits splitting into 6 segments forming a star- shaped structure

11. Sauropus stipitatus

b. Male calyx deeply lobed; fruits not splitting as above

12

12 a. Branchlets terete; leaves membranous; lateral nerves 7 - 8 pairs; male pedicels 1.5 - 4 mm long; male calyx concave-cupular (bowl-shaped) with oblong-lanceolate acute segments, ca 1 x 1.5 mm; female pedicels 4 - 5 mm long; female calyx segments ovate, acute; fruits somewhat depressed, 8 - 10 x 13 - 15 mm

5. Sauropus gour-maitii

b. Branchlets winged; leaves thinly chartaceous to thinly coriaceous; lateral nerves 4 - 7 pairs; male pedicels 4 - 8 mm long; male calyx cupular to more or less obconic, 2 - 3.5 x 2 - 4 mm; male calyx segments oblanceolate or wedge-shaped, emarginate-sinuate at apex; female pedicels 5 - 13 mm long; female calyx segments orbicular to flabellate; fruits globose to pyriform, 15 - 20 x 18 - 25 mm

10. Sauropus saksenanus

List of Lower Taxa