Dune Thistle

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Family: Daisy (Asteraceae syn. Compositae

Photos for Dune Thistle



Scientific Name:	Actites megalocarpa (syn. Sonchus megalocarpus)	Dune Thistle plant Photo: A J Brown
Other Common Names:	Coast Dune Thistle, Coastal Sow Thistle, Beach Sow Thistle, Beach Thistle
Status:	Native to all Australian States, but not the Northern Territory.
Plant Description:	Erect or ascending, somewhat fleshy, perennial herb to 60 cm high with a creeping rhizome and often clump forming. Leaves are crowded (particularly lower leaves), hairless, often stalkless, elliptic to oblanceolate (backward spear-shaped), 5-20 cm long and 1.5-6 cm wide. Leaf edges are entire to sinuate-pinnatisect (wavy to deeply divided to the midrib) and toothed. Veins are often conspicuously paler than the rest of the leaf. Flower heads 1-2 cm diameter; solitary or in groups on stems from 1-10 cm long. The involucre (flower cup) bracts are about 20 mm long; the outer ones having a row of fleshy or scale-like spines near the base. Flowers are yellow throughout or sometimes with a pale purplish base and the ‘petals’ (each is actually a single flower) are 6-10 mm long. The fruit is a cypsela or achene (dry, indehiscent and one-seeded), 4-8 mm long, with a basal pappus (a ring of hairs above each seed), 7-13 mm long.
Habitat:	Common along the Victorian coastline, growing in sand dunes and on exposed cliffs. Has tolerance to salt-spray environments.
Comments:	Dune Thistle belongs to a group of mainly yellow-flowered daisies in the Tribe Lactuceae. The plants in this tribe are characterised by having a basal rosette of leaves (flat-weeds), milky sap in their stems and their flower-heads consisting entirely of ray florets (i.e. no ‘eye’ to the daisy). See Key to Yellow Daisy Flat-weeds.


Photos for Dune Thistle



Leaves of Dune Thistle Photo: A J Brown	Dune Thistle flower-bud Photo: A J Brown
Emerging flowers of Dune Thistle Photo: A J Brown	Dune Thistle flowers Photo: A J Brown
Dune Thistle flowers Photo: A J Brown