Common name: Flower-of-an-Hour
Hibiscus trionum L. APNI*
Description: Annual herb or short-lived perennial with variously dissected leaves.
Lower leaves circular, lamina 1.5–2.5 cm diam.; upper leaves deeply 3–5-lobed, the lobes oblong or lanceolate, lamina 1.5–4 cm long, margins toothed.
Epicalyx segments 10–14, free, linear, 8–10 mm long. Calyx shortly 5-lobed, with 20–25 dark raised veins, 15–20 mm long; inflated after flowering. Corolla 1.5–3 cm long, yellow, cream or white with a dark purple basal spot.
Capsule 15–20 mm long, ovoid, dark, with long scattered simple hairs.
Distribution and occurrence: Widespread, especially in disturbed sites.
NSW subdivisions: NC, CC, SC, NT, CT, ST, NWS, CWS, SWS, NWP, SWP, NFWP, SFWP
Other Australian states: Qld Vic. W.A. S.A. N.T.
Some botanists recognize 2 taxa within this species. Plants in the far west of the State are sometimes referred to as var. vesicarius Hochr.; they are more robust with fewer deeply lobed leaves and usually found on clay soils after flooding or heavy rains. This variety is indigenous to northern and inland Aust. Var. trionum with very dissected leaves is a widespread weed of habitation and cultivation in E Aust. and SW W.A. and is almost certainly introduced. It is not known to what parts of the world it is native.
Text by A. S. Mitchell & E. H. Norris
Taxon concept: Flora of NSW 1 (1990)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.