Sida alba L.

Malvaceae, Bernard Verdcourt & Geoffrey Mwachala. Pavonia, B Verdcourt; Kosteletzkya, OJ Blanchard Jr.; Gossypium, P Fryxell & B Verdcourt. Flora of Tropical East Africa. 2009

Type

Type: Cult. Hort. Upsala, Linn. Herb. 866/2 (LINN, lecto.)

Morphology General Habit

Annual, perennial or subshrubby herb 10–90 cm tall, often branched from base, the stems erect or slightly decumbent, densely stellate-pubescent, later glabrescent and often purplish brown

Morphology Leaves

Leaves discolorous, elliptic or oblong, 0.8–5 × 0.5–3 cm, acute to rounded at the apex, truncate to rounded at base, regularly sharply serrate, dark green and thinly pubescent above, white or grey tomentose beneath; petiole 0.5–2.5(–4) cm long; stipules linear-subulate, 6–10 mm long, often with spurs on stem at their base

Morphology Reproductive morphology Flowers

Flowers solitary in leaf axils or in 4–5-flowered clusters; pedicel 0.3–2.5 cm long; calyx 4–6 mm long, cupular, 10-ribbed, lobed to about the middle, pubescent, the lobes triangular, acute, apiculate

Morphology Reproductive morphology Flowers Corolla

Corolla white, yellow or cream-buff; petals 4–6 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens

Staminal column 2 mm long, glabrous

Morphology Reproductive morphology Fruits

Mericarps 5, 2–3 mm long excluding the birostrate beak with awns 2 mm long, puberulous; basal part of back thin, white and papery, breaking up to release the seed; sides thin walled, striate, the lateral edges distinct and straight.

Ecology

Grassland, grassland with scattered trees and bushes, Acacia woodland, riverine flats, roadsides, weed in old cultivations, wheat etc., often on black cotton soil; 450–1900 m

Note

I have followed Marais (1987) and Vollesen (1995) in keeping S. alba and S. spinosa separate but Sivarajan & Pradeep (Malv. S. Penins. India: 280 (1996)) and many others combine them.

Distribution

Flora districts: U1 U2 U3 U4 K1 K2 K3 K4 K5 K6 T1 T2 T3 T4 T6 T8 Range: Widespread in tropical and South Africa, Arabia, Mascarenes, also in India and America

Malvaceae, A. W. Exell. Flora Zambesiaca 1:2. 1961

Morphology General Habit

Annual or perennial woody or suffruticose plant 30–75 cm. tall, often branched from the base, with somewhat virgate erect or occasionally somewhat trailing branches, covered with a dense short stellate pubescence; stems faintly angular to terete, often soon purplish-brown in colour, at length glabrescent.

Morphology Leaves

Leaf-lamina 2–5 × 0·5–3 cm., usually narrowly ovate but varying from oblong to lanceolate or ovate-lanceolate, apex usually narrowed and subacute but often somewhat rounded, margin sharply and regularly serrate, base usually truncate to rounded sometimes somewhat cordate, upper surface dark green drying brown, thinly and shortly pubescent, glabrescent, lower surface whitish to ash-grey, softly tomentellous; petiole up to c. 3 cm. long, slender, somewhat purplish in older leaves, shortly pubescent, with a callus at the base that is often shortly spinescent; stipules 6–10 mm. long, usually persistent, setaceous.

Morphology Reproductive morphology Flowers

Flowers white to yellow, solitary or fascicled in the leaf-axils; pedicels rarely more than 15 mm. long, slender to filiform, articulated in the upper 3–5 mm.

Morphology Reproductive morphology Flowers Calyx

Calyx c. 6 mm. long, cupular, 10-ribbed, tomentellous, lobed to about the middle; lobes deltoid, acute, minutely mucronate-apiculate.

Morphology Reproductive morphology Flowers Corolla

Petals 5–6 mm. long.

Morphology Reproductive morphology Fruits

Mericarps 5, 4–5 mm. long (including the awns), finely reticulate, with 2 setaceous awns, opening somewhat irregularly at the base.

Morphology Reproductive morphology Seeds

Seeds c. 1·5 mm. long, dark brown, almost smooth, glabrous.

Malvaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:2. 1958

Morphology General Habit

A woody herb, with branches sometimes lax and trailing

Morphology Reproductive morphology Flowers

Flowers small, white.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Erect annual herb or subshrub, up to c. 1 m tall; stems puberulous to pubescent

Morphology Leaves

Leaves with 0.5–2.5(–4) cm long petiole; blade ovate to ± narrowly elliptic, 1.5–5 x 0.7–3.3 cm, rounded or somewhat cordate at the base, acute to rounded at the apex, with dentate margins, sparsely pubescent above, shortly tomentose beneath

Morphology Reproductive morphology Inflorescences

Flowers solitary or clustered in leaf axils; pedicels 3–22 mm long

Morphology Reproductive morphology Flowers Calyx

Calyx 4–6 mm long, enclosing the ripe mericarps

Morphology Reproductive morphology Flowers Corolla

Petals 4–6 mm long, white to yellow

Morphology Reproductive morphology Fruits

Mericarps 5, c. 3 mm long and with a pair of 1–2 mm long puberulous awns, basal part of back thin and papery, breaking up to release the seed, sides striate.

Distribution

C2; S2, 3; widespread in tropical and southern Africa and in tropical America.

Ecology

Altitude range 10–520 m.