Plants → Asclepiadaceae → Gomphocarpus
Gomphocarpus physocarpus E.Mey.
Comm.Pl.Afr.Austr. 202 (1837)
Conservation Status:
Alien
Name Status:
Current
Brief Description
Grazyna Paczkowska,
Monday 28 October 1996
Slender, erect perennial, herb or shrub, 0.5–2 m high. Fl. white, cream, Dec/Mar–Apr. Peaty sand, sandy clay. Salt or winter-wet lake edges. Distribution: SW: JF, SWA.
Scientific Description
Amanda Spooner, James Carpenter, Gillian Smith and Kim Spence,
Thursday 21 August 2008
Common name(s). Balloon Cottonbush; Swan plant.
Habit. Erect, slender shrubs (with milky sap), up to 2 m high. Spines present; associated with fruits (spines very soft, to 7 mm long).
Leaves. Opposite, decussate, simple, petiolate (shortly) or subsessile, petiole 0–10 mm long. Leaf blade 68–120 mm long, 7–20 mm wide, undissected, elliptic (narrow-lanceolate) or oblong, base tapering (attenuate, cuneate), margins entire, apex acute or apiculate. Blade mainly glabrous (some specimens with very short hairs on lower midrib); hairy.
Flowers. In umbels (or umbelliform, 5–10 flowered); predominantly white or cream, regular, pedicellate, pedicel 15–20 mm long, perianth 2 -whorled. Calyx 2.5–4 mm long (shortly hairy), 5 sepals, all sepals joined (very shortly). Corolla 7–12 mm long (lobes reflexed), 5 petals, all petals joined (tube short). Stamens 5 (with corona of complex lobes), adnate to the perianth, all alternating with the corolla parts, coherent to each other (connate into column of corona). Anthers non-versatile (basifixed), dehiscent at apex. Ovary syncarpous, superior, 2 -celled. Ovules numerous. Styles 2 (joined at apex), simple.
Fruit. Dehiscent, a follicle (globose at maturity, abruptly acute), non-fleshy, 50–75 mm long, 46–55 mm wide.
Distribution. Australian: Western Australia, South Australia, Queensland, New South Wales, Victoria. Alien to Australia, alien to Western Australia, naturalised. Native: tropical and southern Africa.
Habitat. Amongst medium trees, grassland; in sand, loam, clay (peaty sand; loam over granite); occupying lake edges (salt or winter-wet), creeklines, watercourses; growing in disturbed natural vegetation.
Flowering period. February, March, April, July, December.
Additional differences from related species. Gomphocarpus physocarpus differs from G. fruticosus in having larger fruit (50–75 x 20–55 mm cf 23–59 x 22–30 mm) and in the fruit having no attenuate apex.
Descriptions are sourced from the Weed Information Network project, Western Australian Herbarium.
Descriptions were generated using DELTA data format and DELTA software: Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998).
