Hibiscus trionum L.
bladder hibiscus
Annual or biennial herb up to 0.5 m high, not armed. Stems moderately to densely clothed in stellate hairs when young, becoming ± glabrous. Lvs sparsely hairy with simple and stellate hairs; lower lvs suborbicular and entire to coarsely serrate; stem lvs palmately 3-5-lobed, 1-6 cm long; segments serrate to pinnatifid; petioles 5-15-(30) mm long; stipules linear, 3-8 mm long, persistent. Fls solitary and axillary, or 1-3 and pseudoterminal; epicalyx segments (8)-10-13, free ± to base, linear-lanceolate; calyx campanulate; calyx teeth ovate-triangular, = or somewhat < tube, membranous, with long, few-rayed stellate hairs on veins and margins, scattered short many-rayed stellate hairs on teeth, and short simple hairs within. Petals white to pale yellow, with dark brown, red, purplish or orange markings at base, c. 20-40 mm long. Capsule separating into 5 cells at dehiscence, loosely enclosed by calyx. Seeds brown, papillate, 2-2.5 mm long.
N.: throughout; S.: Nelson, Westland, Canterbury, Otago.
Origin uncertain, possibly Africa, now widespread 1840
Coastal habitats, waste places, gardens, cultivated land.
FL Oct-Mar.
This sp. has usually been treated as part of the indigenous flora, although doubt is often expressed about its status. As it is not known anywhere in the tropical Pacific and occurs in E. Australia only as a casual, there is little doubt that it is also alien to N.Z. Within N.Z. plants are quite variable in fl. size and colour and were first recorded as H. vesicarius.
