Asystasia gangetica

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Asystasia gangetica

Description

Shrub or subshrub to 1.5 m tall, creeping or climbing. Branches ± quadrangular, sometimes furrowed on both sides, often constricted above nodes, these pubescent, glabrate or pubescent with trichomes disposed in decussating lines. Petiole 2-30 mm long; blade ovate, 15-45(-90) x 5-30(-50) mm, apex abruptly acuminate, truncate at base, glabrous or minutely pubescent on upper surface, minutely and sparingly pubescent on primary and secondary veins on lower surface, margin ± entire to shallowly erose; leaves subtending peduncles reduced, narrower than cauline leaves. Inflorescence an axillary or terminal, often secund raceme, 4-10(-20) cm long; peduncle to 5.5 cm long; bracts in opposite pairs on either side of peduncle, triangular, 0.8-2 x 0.75-1.5 mm, pubescent with eglandular trichomes on outer midrib and margins; bracteoles similar to bracts but smaller. Flowers single at nodes, sparse; pedicel 0.5-1.5 mm long. Calyx 5-10 mm long, glabrous or pubescent without, with glandular and eglandular trichomes; corolla blue, mauve or white, appearing yellowish when dry, 30-40 mm long, inconspicuously puberulous without, with glandular and eglandular trichomes, tube and throat 15-20 mm long, tube half the length of throat, throat 13 mm wide, lobes rounded, 8.5-15 mm in diameter, conspicuously and coarsely reticulate veined; stamens ± equal, each pair arising 3.5-4 mm above base, free for about 4 mm, filaments near base with 2 lines of trichomes; thecae sparsely eglandular and glandular pubescent dorsally just above base; ovary pubescent, style 14-16 mm long, basally pubescent. Capsule 20-25 mm long, pubescent, retinacula 2 in each valve, often 1 and its seed not developed fully; seeds 4 x 4 mm, smooth on sides.

Distribution

Asia present, Guianas present, Malaysia present, tropical Africa present, tropical America
Native to tropical Africa, Asia and Malaysia; introduced into tropical America where it is cultivated or persists as an escape; 15 collections studied from the Guianas (GU: 4; SU: 4; FG: 7).

Phenology

Flowering .