Sida acuta Burman f.

Pantropical Weed.

A pantropical weed.

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Flower

In axillary, solitary, sometime clustered into lax racemes; pale yellow. Flowering throughout the year.

Fruit

A schizocarp, enclosed in the calyx, margin at apex toothed; mericarps 6, 4-hedral with 2 awns; seeds 3-gonous. Fruiting throughout the year.

Field tips

Leaves 3-5-nerved from base. Stipules at the same node unequal. Awns of mericarp glabrous.

Leaf Arrangement

Alternate-spiral

Leaf Type

Simple

Leaf Shape

Oblong-lanceolate or elliptic

Leaf Apex

Acuminate

Leaf Base

Obtuse

Leaf Margin

Serrate

"

Subshrubs or herbs erect, 1-2 m tall. Branchlets pilose or subglabrous. Leaves ± distichous; stipules filiform, 4-6 mm, often longer than petiole, usually persistent; petiole 4-6 mm, sparsely pilose; leaf blade ovate, oblong, lanceolate, or linear-lanceolate, 2-5 × 0.4-1 cm, both surfaces glabrous or sparsely stellate pilose, rarely with simple hairs adaxially, base obtuse, margin dentate, sometimes partly entire toward its base, apex acute or acuminate. Flowers solitary or paired, axillary, sometimes congested at stem apex. Pedicel 4-12 mm, pilose, articulate at middle. Calyx shallowly cup-shaped, connate in basal 1/2, ca. 6 mm, mostly glabrous, margins often ciliate, lobes 5, caudate. Corolla yellow, less often white or yellow-orange, 8-10 mm in diam.; petals obovate, 6-7 mm, ciliate, base attenuate, apex rounded. Filament tube ca. 4 mm, sparsely hirsute. Schizocarp nearly globose; mericarps (4-)6(-9), segmentiform-tetrahedral, ca. 3.5 mm, basally transversely ridged, side walls reticulate-veined, glabrous, apex beaked, ± extending into 2 awns, apically dehiscent. Seed trigonous, ca. 2 mm, glabrous except around hilum. Fl. winter-spring.