Single Star Heliotropium

Gebel Elba.

Southeast Egypt, tropical Africa, Arabia, Afghanistan, tropical Asia, China, Australia.

Mountain slopes, stony wadis.

Annual or short-lived perennial.

Perennial, prostrate to procumbent or ± erect and up to 28 cm tall, usually much branched from the base, appressed hairy. Leaves 6-30 x 2-4 mm, linear-lanceolate, acute, appressed, strigosely hairy on both surfaces, with short hairs. Hairs less than 1 mm long. Inflorescence bracteate, 2-10 cm long, simple or paired. Lower bracts lanceolate, 2-3 mm long; lower flowers with pedicels up to 2 mm long. Calyx 2.5-3 mm long, 5-partite, lobes lanceolate, hairy to the outside, glabrous within, somewhat puberulous at the throat; lobes spreading, broad. Anthers 0.7-0.8 mm long, ± adnate when young, attached c. 0.6 mm from base of corolla tube. Stigma conical, 0.6-0.7 mm long, minutely pilose towards tip; stigmatic ring prominent. Style slightly shorter, glabrous. Fruit ± globose, depressed or not, 4-lobed, dense pilose. Nutlets 4, dark brown, c. 1.5 mm long.

Two subspecies may be recognised

Herbs perennial, rarely annual, 15-30 cm tall. Stems numerous, slender, prostrate or ascending, base woody, densely appressed strigose. Leaves crowded; petiole 0.5-1 mm, or ± sessile; leaf blade linear-lanceolate, 3-10 × 1-1.5 mm, appressed strigose, margin usually revolute; midvein prominent abaxially, concave adaxially, without evident lateral veins. Cymes scorpioid, slender, 2-6 cm; bracts 1-3 mm. Flowers sparse, unilateral. Calyx 2-3 mm; lobes lanceolate, sparsely strigose. Corolla white, tubular or funnelform, 3-4 mm, widest at middle, ca. 1 mm wide; throat constricted, glandular, sparsely pubescent; limb 3.5-4 mm wide; lobes suborbicular, with folds above middle, densely hispid outside. Anthers ovate-lanceolate, 0.5-0.7 mm, apices thickened, coherent. Ovary globose, glabrous. Style short, evident; stigma conical, base ringlike, ca. 3 mm wide, apex short pubescent. Fruit compressed globose, ca. 2 mm in diam., densely strigose-hirtellous, divided at maturity into 4 1-seeded mericarps; mericarps trigonous-ovate, ca. 1 mm. Fl. and fr. Jul-Sep. 2n = 22, 26, 32, 64.

Sandy places, woods on coastal slopes. Fujian, Guangdong [Afghanistan, Bhutan, Cambodia, India, Kashmir, Laos, Myanmar, Nepal, Pakistan, Thailand, Vietnam; Africa, Australia].

Lithospermum chinense Hooker & Arnott.