Species

Hibiscus tridactylites

Etymology

Hibiscus: Name of very ancient origin used by the Roman poet Virgil for the marsh mallow plant.

Common Name(s)

bladder ketmia

Authority

Hibiscus tridactylites Lindl.

Family

Malvaceae

Flora Category

Vascular - Exotic

Structural Class

Dicotyledonous Herbs other than Composites

Distribution

Naturalised to New Zealand where it has been discovered in Auckland City (2013). Indigenous to Australia where it can be a troublesome weed of agricultural land and crops (such as cotton, soybean, grain and sorghum) ( Craven et al. 2011)

Habitat

Uncommon urban weed. Occasionally cultivated (and then erroneously referred to as Hibiscus trionum)

Features

Herb 0.15-0.4(-1.3) m tall. Branchlet with fine stellate hairs 0.4-0.8 mm long and coarse stellate hairs 0.2-0.8 mm long, with sparse fine bristles 0.25-0.4mm long. Stipules more or less persistent, 4-6 mm long. Mid-stem and distal leaves 3-lobed, lobing extended to the apex of the petiole, the primary lobes themselves strongly lobed, palmately veined; lamina of mid-stem leaves 20-90 mm long, 25-80 mm wide, in overall shape ovate, broadly ovate, or suborbicular with stellate hairs and fine bristles, margin sparsely serrate, lobe apex rounded; petiole 20-50 mm long with indumentum similar to that of the branchlet; foliar nectary absent. Flowers solitary in leaf axils, chasmogamous, pedunculate; peduncle 15-60 mm long, with stellate hairs and with sparse fine bristles; pedicel 0.25-0.6 mm long, indumentum dissimilar to that of peduncle (the hairs slightly denser and longer). Epicalyx 10-13-segmented, 6.5-11.0 mm long, segments linear, free at the base, shorter than the calyx. Calyx at anthesis 11-14 mm long, distinctly accrescent in fruit, with stellate hairs and coarse bristles, without prominent marginal ribs; lobes triangular, acute at the apex; calyx nectary absent. Petal 22-30 mm long, yellow or cream with a large purplish basal petal spot. Staminal column straight. Staminal column at the apex 5-toothed. Staminal column 7-12 mm long with the stamens distributed along the distal 1.6-4.0 mm of the column; staminal filaments 2-3 mm long; anthers yellow; pollen yellow. Style (including style branches) exserted 2-3 mm beyond the apex of the staminal column; style branches 5, 0.7-0.9 mm long; stigmas capitate, 0.4-0.6 mm across, stigmatic hairs 0.2-0.3 mm long. Ovary hairy. Fruit capsulate. Capsule hairy, 12-16 mm long. Seed 2.3-2.5 mm long, subreniform, papillate-pubescent and smooth between the hair pustules.

Similar Taxa

Hibiscus richardsonii and H. trionum "diploid New Zealand race" from which H. tridactylites differs by the mid-stem and distal leaves lobed to the apex of the petiole, by the pedicel which is 0.25-0.6mm long, and tetraploid (2n = 56) rather than diploid (2n = 28) chromosome number. From Hibiscus richardsonii it is also readily distinguished by the purple basal petal spot (absent in H. richardsonii).

Flowering

October - June

Fruiting

December - August

Propagation Technique

Easily grown from fresh seed. In New Zealand probably not invasive (unlike Australia) but seed is long-lived (and overtime a large seed bank is developed) and prone to germinate following ground disturbance.

Chromosome No.

2n = 56

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Year Naturalised

2013

Origin

Australia

Notes

Herbarium evidence suggests that H. tridactytlites has been occasionally cultivated in New Zealand (Auckland) for the last 60 or so years. The sole, wild occurrence was of a plant that appeared in a bark garden. However, H. tridactylites had not knowingly been cultivated in that area previously.

Attribution

Fact Sheet Prepared for NZPCN by: P.J. de Lange (4 March 2013). Description from Craven et al. (2011).

References and further reading

Craven, L.A.; de Lange, P.J.; Lally, T.R.; Murray, B.G.; Johnson. S.B. 2011. The indigenous Australasian bladder ketmia species (Hibiscus trionum complex, Malvaceae). New Zealand Journal of Botany 49: 27–40.

Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.

This page last updated on 9 Aug 2013