Sacramento Burrbark

Triumfetta semitriloba is very easily confused with T. rhomboidea.

Shrubs or perennial herbs, to 1 m or more tall. Branchlets pubescent, hairs simple and stellate. Petiole 0.5-6 cm; leaf blade broadly ovate, sometimes obscurely 3-lobed, 4-8 × 3-6 cm, membranous, abaxially grayish green, stellate pubescent,
adaxially pubescent, hairs simple, basal veins 3, base rounded, rarely shallowly cordate, margin irregularly serrate-dentate, apex acuminate; upper leaves usually oblong. Cymes 2 or 3 per axil; peduncle 1-2(-3) mm. Flower buds cylindrical, ca. 4 mm, pubescent. Pedicel 2-3 mm. Sepals linear, ca. 6 mm, abaxially stellate pubescent, appendage subapical, ca. 0.5 mm, pubescent. Petals narrowly elliptic-obovate, ca. as long as sepals, Stamens 15 or more, filaments glabrous. Ovary 3-loculed, spiny; style 3-5 mm; stigma ± 3-lobed. Capsule globose, body 3-5 mm in diam., 3-loculed, indehiscent, glabrescent; spines 1.5-2 mm, retrorsely pilosulose at base, conical at base, tip hooked. Seeds 1 or 2 per cell. Fl. Oct-Jan.

Fields, wastelands. S Taiwan [Philippines; tropical America].