Gisekia pharnaceoides L.

Eastern desert.

Egypt.

Sandy desert soils.

Annual.

A plant of dry sandy places. Very variable in form and size; plants found near water or cultivated places are larger and the flowers have longer pedicels, the filaments are with a broader base. The plant is medicinal and used as a purgative.

Collections from Iran and Pakistan with winged mericarps have been described as var. alata M. G. Gilbert.

Plants 2.5-3.0 cm long. Roots slender. Leaves 0.8-4.0 cm long, linear lanceolate to spathulate, with raphides on the undersurface. Sepals ovate, c. 1.8 mm long, persistent, margin white. Stamens 5, alternating with the sepals, less than 1 mm long; filaments dilated at the base. Carpel c. 1 mm long; ovary sub-globose, styles 5, free, lateral. Fruit parts with wall more or less fimbriate and with raphides. Seeds c. 1 mm long, minutely punctate, shiny.

Herbs annual, 20-50 cm, prostrate. All parts streaked with linear white raphides. Petiole poorly defined, 2-10 mm; leaf blade elliptic, lanceolate, or spatulate, 1-2.5 cm × 4-10 mm, both surfaces with many white raphides, base attenuate, apex obtuse or subacute. Inflorescences mostly sessile, apparently axillary, densely umbel-like. Flowers 5-20. Pedicel 3-5 mm. Tepals 5, green (to red), ovate, 1.5-2 mm, apex acute. Stamens 5, ca. 1 mm; filaments flattened and dilated at base. Carpels 5; styles short. Mericarp reniform, mostly spiny tuberculate, sometimes also some smooth, surrounded by persistent tepals. Seeds black, smooth, minutely pitted. Fl. summer-autumn, fr. winter.

Distribution: Africa, Arabia, India, Ceylon, Afghanistan and W. Pakistan.

Fl. Per.: Aug.-Oct.

Open, sandy habitats, often near the sea;; low elevations. Hainan [Afghanistan, India, Pakistan, Thailand, Vietnam; tropical and subtropical Africa; introduced in North America (SE United States)].