Family: Polygonaceae
Emex australis
Citation:
Steinh., Annls.Sci. nat. sér. 2, 9:195 (1838).
Synonymy: Not Applicable Common name: Three-cornered jack, spiny emex, double gee, Cape spinach, Jackie, prickly Jack, goat-heads, devil-face.
Description:
Glabrous annual with many or few prostrate or ascending stems to 50 cm long, sometimes reddish; leaves petiolate, ovate, truncate or cordate at the base, rarely more than 6 cm long.
Female flowers subsessile; fruiting perianth 7-10 mm wide, with a somewhat cuneate base, the spines spreading or erect-spreading, the inner perianth-segments broadly ovate, with shortly pointed apices, closing over the apex of the fruit.
| habit and fruit
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Image source: fig. 94a in Jessop J.P. & Toelken H.R. (Ed.) 1986. Flora of South Australia (4th edn).
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Published illustration:
Cunningham et al. (1982) Plants of western New South Wales, p. 229.
Distribution:
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All mainland States. Native to South Africa (where it was first reported in 1685); naturalised in North America; Hawaii; New Zealand.
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Conservation status:
naturalised
Flowering time: July — Nov.
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SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia
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Biology:
May reduce crop productivity by competition and both the spines and the toxic oxalates cause trouble with stock.
Taxonomic notes:
First recorded in S.Aust. in 1833.
Author:
Not yet available
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