Family: Asteraceae
Ambrosia psilostachya
Citation:
DC., Prod. 5:526 (1836).
Synonymy: A. artemisiifolia sensu J. Black, Fl. S. Aust. 602 (1929), non L.
Common name: Perennial ragweed, western ragweed.
Description:
Stoloniferous perennial to 2 m high, forming dense colonies; stems erect, simple or branched in the upper portion, striate, scabrous; woody at the base; leaves broadly lanceolate, shortly petiolate, 5-12 cm long, pinnatipartite with lanceolate often toothed segments 2-4 mm wide, green, pubescent with appressed hairs.
Racemes several, erect, terminating branches at the top of the plant, 3-12 cm long; male capitula numerous, c. 3 mm diam., on pedicels c. 1 mm long; florets numerous, not exceeding the involucre, a pale greenish-yellow; female capitula solitary, rarely paired, in axils.
Fruiting capitula turbinate, 3-4 mm long, reticulate, 5-ribbed, with 5 short spines above and a longer central beak at the apex.
| Twig, male and female capitula and portion of leaf.
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Image source: fig. 642a in Jessop J.P. & Toelken H.R. (Ed.) 1986. Flora of South Australia (4th edn).
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Published illustration:
Parsons (1973) Noxious weeds of Victoria, p. 88).
Distribution:
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Weed of waste ground, roadsides, stream banks and irrigated land.
S.Aust.: MU, SL. W.Aust.; N.S.W.; Vic.
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Conservation status:
naturalised
Flowering time: most of the year.
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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:
No text
Author:
Not yet available
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