Pilea usambarensis Engl.

Perennial herb with prostrate and ascending stems, up to 0.4(–0.5) m. high.. Stems juicy, glabrous.. Leaves of a pair subequal or one with longer petiole than the other; stipules short, persistent but insignificant, broadly triangular to almost rim-like, up to 0.8 mm. long, translucent, whitish or greenish; petiole 0.5–4 cm. long, glabrous or with a few hairs at connection with lamina; lamina very variable in size and shape, from almost circular or broadly ovate to lanceolate or elongate, 1–11 cm. long, 1–4.5 cm. wide, base truncate to broadly cuneate, margin serrate, with 3–15 teeth on each side, apex rounded, acute or acuminate; lateral nerves 3–11 pairs, basal pair reaching 2nd–4th tooth from the apex; glabrous on both sides, or rarely with scattered stiff hairs above and spreading hairs on the nerves below, upper surface with regularly scattered linear cystoliths, lower surface with scattered hydatodes.. Inflorescences peduncular heads, usually 2 together in the upper leaf-axils, usually the 2 of a pair of the same sex; ♂ inflorescences globose cymose heads, 0.8–1.3 cm. in diameter, on peduncles 1.5–5.5 cm. long; ♀ inflorescences globose cymose heads, 0.4–0.6 cm. in diameter, on peduncles 0.8–1.4 cm. long, sometimes the inflorescence-axis branched 2–3 times below the primary head, so the inflorescence consists of up to 5 heads (rarely only 2, one above the other, as on an unbranched inflorescence-axis).. Male flowers on pedicels 0.8–1.4 mm. long; perianth ± 1 mm. in diameter; perianth 3-merous, tepals with subapical appendage.. Female flowers subsessile; perianth ± 1 mm. long, one perianth-segment ± 1 mm. long, with a subapical appendage up to 0.8 mm. long, the 2 lateral perianth-segments very short.. Achene ovoid, compressed, ± 0.8 mm. long, brown.