Plate 42. COMMELINA benghalensis. Cape Province, Natal, Transvaal.

Commelinaceae. Tribe Commelineae.

Commelina, Linn.; Benth. et Hook. f. Gen. Plant. vol. iii. p. 847.

Commelina benghalensis, Linn. Sp. Pl. 41; Fl. Cap. vol. vii. p. 9.

A common species in certain habitats in South Africa, and extending to Tropical Africa, throughout India to Japan, and the Moluccas. On account of its easy cultivation and the exquisite deep shade of blue of the petals, it deserves more recognition from gardeners, and should be at least as great a favourite as species of Tradescantia (The Wandering Jew). The floral structure shows interesting modifications in the stamens, and a study of the method of pollination would certainly bring to light some interesting facts. This plant often produces at the base modified (cleistogamic) flowers which burrow into the ground and produce small capsules.

The original drawing from which our figure has been reproduced was prepared by Miss Page and loaned by the Curator of the Bolus Herbarium. The plants flowered in March and April at the National Botanic Gardens, Kirstenbosch (No. 1232/18), and were sent by Mr. G. Hay from Louis Trichardt, Transvaal.

Description:—A diffuse herbaceous plant. Stem 15-80 cm. long. Leaves 3-8 cm. long, 1·5-3·5 cm. broad, ovate or elliptic-ovate, acute, contracted at the base into a sheath often ciliate with reddish hairs, and usually wavy margins. Flowers partly enclosed in a green hairy spathe, the topmost flower long-exserted. Sepals 3; the two side sepals more or less orbicular; the odd sepal elliptic. Petals 3; the two side petals dark blue, semi-orbicular, produced at the base into a distinct claw; the odd petal small, ovate-elliptic. Stamens 6, divided into three sets; three stamens barren, forming staminodes; the three side stamens blue; one stamen yellow, with two appendages at the back of the anther. Ovary sub-globose, 3-celled; style cylindric; stigma simple. Fruit obovoid, 3-celled. Seeds more or less oblong, wrinkled.

Plate 42.—Fig. 1, inflorescence in bud; Fig. 2, the same with half of spathe removed; Fig. 3, side sepal × 2; Fig. 4, odd sepal × 2; Fig. 5, side petal × 2; Fig. 6, odd petal × 2; Fig. 7, stamens and pistil × 3; Fig. 8, small anther (blue) × 5; Figs. 9, 10, larger anthers (yellow), front and back view × 5; Fig. 11, fruit × 4; Fig. 12, transverse section of fruit; Fig. 13, seed, enlarged.

F.P.S.A., 1922.

M. Page del.