Hibiscus trionum
Common names
bladder hibiscus
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Brown, Yellow
Detailed description
Annual to short-lived perennial herb up to 0.8 m tall. Stems densely clothed in stellate hairs when young becoming glabrescent with age. Lower leaves glabrescent, suborbicular, entire to coarsely serrated, stem leaves green at first becoming purple-red with age, palmately 3-5-lobed, 20-80 mm long, somewhat hairy, segments deeply and coarsely lobed or serrated. Flowers solitary and axillary, often with 1-3 flowers pseudoterminal; epicalyx segments (8-)10-13, free to near base, linear-lanceolate, calyx campanulate; calyx teeth ovate-triangular, somewhat < tube in length. Petals 20-30 mm long, pale yellow to yellow, basally marked dark brown, purple-red or maroon. Capsule long persistent, with papery calyx. Seeds 2-2.5 mm, papillate
Similar taxa
Hibiscus richardsonii, has been confused with this species. It differs by the smaller, finely serrated leaves, smaller uniformly cream flowers whose petals lack the basal maroon blotch, and by its smaller seeds (de Lange et al. 2010; Craven et al. 2011). It is has a different nrDNA ITS sequence.
Habitat
Most collections come from urban or formerly urban situations. The earliest collections come from Reef Point and were gathered between 1897, when that area was a thriving gum digging settlement. Some modern gatherings come from indigenous habitats, but these are usually near old camp sites or picnic spots.
Detailed taxonomy
Genus
Family
Taxonomic notes
The New Zealand race of Hibiscus trionum is diploid (all others chromosome counts for this species reported in world literature are tetraploid - see Murray et al. 2008). Further the New Zealand race of H. trionum has, so far, yet to be matched with any of the other races of “H. trionum” seen in Australia, USA, Africa and Western Europe. There is thus a slight possibility that the plant described here is actually indigenous - currently it is known in botanical literature as Hibiscus trionum “N.Z. diploid naturalised race” (Craven et al. 2011) - further reseaerch is needed.
Endemic genus
No
Endemic family
No
Ecology
Flowering
October - May
Fruiting
May be present all year
Year naturalised
c.1860 - possibly 1890.
Origin
Unknown. The type is from a garden plant collected from Florence, Italy
Reason for introduction
Ornamental
Tolerances
Frost-sensitive and in cold climates behaves as an annual.
Life cycle and dispersal
A short-lived perennial which reproduces by seed. Seed germinates readily, and remains viable for many years. Usually spreads from garden situations. Though some occurrences stem from deliberate, misguided naturalisations.
Other information
Etymology
hibiscus: Name of very ancient origin used by the Roman poet Virgil for the marsh mallow plant.
Referencing and citations
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.
de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R.; Sawyer, J.W.D. 2010: Threatened Plants of New Zealand. Christchurch, Canterbury University Press. 471pp.
Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.
Murray, B.G.; Craven, L.A,; de Lange, P.J. 2008: New observations on chromosome number variation in Hibiscus trionum s.l. (Malvaceae) and their implications for systematics and conservation. New Zealand Journal of Botany 46: 315-319.
Attribution
Description based on Craven et al. (2011). Fact sheet prepared by P.J. de Lange (September 2010)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hibiscus trionum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hibiscus-trionum/ (Date website was queried)