Sida abutifolia Kunth, spreading sida, creeping yellow sida. Perennial herb, from woody root, not rosetted, several–stemmed at base, casually branched on trailing to procumbent axes or prostrate on bare ground, < 25 cm tall; shoots with only cauline leaves, leaves widely spaced and oriented away from lower side, short stellate–hairs with arms mostly < 0.2 mm long and some green structures with unbranched hairs.
Stems cylindric, < 1 mm diameter, tough, yellow–green, lax, internode > petiole or petiole + blade, stellate hairs mostly with 1—3 arms.
Leaves helically alternate, simple, petiolate, with stipules; stipules 2, attached at base of petiole and with node, spreading, linear, 1.7—2.2 mm long, green, stellate–hairy and with slightly longer unbranched hirsute hairs; petiole slender, cylindric, 3.5—10 mm long, ascending to spreading, stellate–hairy and hairs with mostly 6+ arms; blade ovate, (3—)5.5—24 × (3—)4.5—8 mm, dull, truncate to subcordate or cordate at base, crenate to dentate on margins with < 20 teeth per blade, having acute tooth at tip, with 3 principal veins at base and midrib sunken on upper surface and principal veins raised on lower surface, stellate hairs mostly 6—10–armed, with unbranched hirsute hairs on margins.
Inflorescence flowers solitary, axillary, not flowering at all nodes of canopy, without bracts, green surfaces having mostly short stellate hairs; bractlet = cauline leaf including stipules; pedicel slender, initially straight and ascending, cylindric, 13—17 × 0.35 mm not increasing in fruit but in fruit to 1 mm diameter, green often aging purplish, with pulvinus 0.45 mm diameter at top immediately beneath horizontal flower, in fruit pedicel widely spreading sharply bent at pulvinus making fruit oriented horizontal, densely stellate–hairy; lacking bracteoles at top of pedicel (no epicalyx).
Flower bisexual, radial, 12—14 mm across; calyx 5–lobed, green, outer (lower) surface densely covered with short stellate hairs; tube broadly funnel–shaped, ca. 3.5 mm long not increasing in fruit, length < width, 10–ribbed; lobes spreading, broad with acuminate tip, ca. 2.5 × 3 mm in fruit leaning inward concealing fruit and having wavy margins, inner surface with hairs having few arms or unbranched; petals 5, fused to base of staminal column, widely spreading, 2–lobed (cordate) fan–shaped, 8—9 × 4.5—5 mm, light orange–yellow (light yellow), with thick stalk at base and principal veins ascending from base raised on both surfaces, glabrous except for several stellate hairs on margin at base; stamens 15—20, monadelphous (fused into a column); column of fused filaments surrounding style and also fused to petals at base, 2.3—2.5 mm long, basal portion concealing ovary conic and ca. 1 mm long, erect cylindric column 0.4 mm diameter, orange–yellow, upper portion with scattered, radiating short hairs; free filaments arising from top of column individually and some unequally forked, spreading to ascending, slender, mostly 0.7—1.3 mm long, orange–yellow; anthers dorsifixed, monothecal, 0.3—0.4 mm long, orange–yellow, longitudinally dehiscent; pollen orange–yellow; pistil 1; ovary superior, hidden beneath staminal column, ovoid conspicuously 5–lobed, 0.8 × 0.9 mm, light green, at top with depressed center, with 5 pairs of short acute horns at top in rings around depressed center, glabrous to midpoint and with mostly short, unbranched hairs above midpoint, 5–chambered, each chamber with 1 ovule; style in depressed center of ovary, exserted, ca. 4 mm long, orange–yellow, 5–branched approaching top of staminal column, the branches curved and spreading; stigmas terminal, capitate, extending at least 0.5 mm beyond anthers, short–papillate.
Fruit schizocarp, of 5 dry, 1–seeded mericarps, before splitting conspicuously 5–lobed and muffin–shaped, ca. 2.5 × 3 mm, with persistent base of style (beak) in depressed center and a ring of 10 acute, inward–facing horns; mericarp indehiscent, wedgelike and somewhat D–shaped but having a pair of short horns at top, ca. 2.5 × 1.5 mm, tan and brown, back glabrous to midpoint and puberulent above midpoint including pair of horns with mostly unbranched hairs.
A. C. Gibson