Asteraceae

DICOTYLEDONS

ASTERACEAE - Daisy Family

Argyranthemum is a genus of 22 species native to Madeira and the CanaryIslands. Two species, both garden escapes, have been recorded as naturalised on limestone cliffs on the Swan River estuary. A. foeniculaceum (Tenerife daisy) is a stout branching perennial to 1m tall. It has greyish, feathery, divided leaves and the 5cm wide flowers with white ray florets are produced in summer. A. frutescens (marguerite) is a more delicate branching perennial that is winter-flowering, with smaller white flowers (3cm) and bright green leaves.
Aster subulatus (bushy starwort) is a common plant in wetlands, wetter wasteland and roadside drains from Gingin to Albany. It is a summer-growing, dark green, spindly, erect annual or biennial to 1.5m, with small leaves closely apressed to the stem. The heads are small, with inconspicuous white or blue ray florets. Native to North America.

Aster subulatus , PH

Berkheya rigida (African thistle) DP is a prickly perennial to 60cm tall, that often forms colonies by rooting at the nodes. The leaves, and the bracts below the flower heads, are stiff and prickly, but the stem does not bear prickles. The flowers are yellow and are produced from late spring to autumn. Currently found only in coastal areas near Augusta, and thought to have been introduced from South Africa in ballast from ships involved in the early timber trade.

Berkheya rigida , GK

Bidens is found worldwide, with two species naturalised in Western Australia. Both are erect annual herbs with four-angled stems, heads in terminal panicles and narrow black fruits with barbed awns at one end. B. bipinnata (beggar's ticks) has deeply lobed, bipinnate leaves, two to three awns and usually no ray florets. It occurs at Kalbarri, Newman and in the Kimberley.
B. pilosa (cobbler's pegs) has pinnate leaves, three to four awns and white or cream coloured ray florets. It is found in the Pilbara and Kimberley. Both favour wetlands, flower in autumn, and are thought to be spread by cattle.

Bidens pilosa , RR

Carduus (thistles) are annuals or biennials with prickly, winged stems, flowering in spring and early summer, that are found as weeds of pasture, wasteland and disturbed bushland in the south-west. Their seeds are carried on a parachute of simple hairs (unlike Cirsium, the spear thistles, that have a feathery parachute). There are about 120 species in Europe, Asia and North Africa, and three have become naturalised in Western Australia.
C. nutans (nodding thistle), once found at Green Range near Albany, has now been eradicated. The bracts under the head in this species are often strongly recurved.
C. pycnocephalus (slender thistle) has prickly wings on the stems that become discontinuous as they get nearer the flower heads, which are usually in clusters of two or three. Each head is cylindrical, up to 1.5cm across, with reddish-purple flowers. It is a common weed of agricultural areas and disturbed bushland from Perth to Esperance. C. tenuiflorus (sheep thistle) is very similar to slender thistle, but the prickly wings on the stem extend right up to the flower heads and the plant is somewhat stouter. Found in agricultural areas and peppermint woodland.

Carduus pycnocephalus , RR

Carthamus lanatus (saffron thistle) DP is an annual from southern Europe that grows to 70cm. The leaves are rigid, with spiny lobes. The yellow flower heads are surrounded by spiny bracts and are borne in terminal clusters. It flowers in spring and summer and is a serious weed of agricultural and pastoral areas as well as disturbed bushland throughout the south-west. Two other species have occasionally been recorded as agricultural weeds in Western Australia,
C. leucocaulos (glaucous star thistle) DP that has purplish florets and C. tinctorius (safflower) which is similar to saffron thistle except for having undivided leaves and darker gold flowers. It is sometimes grown as an oil-seed crop and is an escape from cultivation.

Carthamus lanatus , RR

Centaurea is a cosmopolitan genus of about 600 species, of which three have become naturalised in Western Australia. The commonest and most widespread is
C. melitensis (Maltese cockspur) that occurs from Carnarvon through to the arid zone and across the Nullarbor. It is an erect biennial to 80cm with lobed leaves and yellow, thistle-like flower heads borne terminally or on short branches in the upper axils. The bracts below the heads have a short, often reddish spine. The stems have non-prickly wings. It flowers in spring and summer and is originally from the Mediterranean.
C. solstitialis (St Barnaby's thistle) is a similar plant, also with yellow flower heads, but the bracts have a long yellow spine. The leaves and stem are grey-woolly. It is found principally on the Nullarbor and in the eastern wheatbelt, flowering in summer.
C. calcitrapa (star thistle) is a much-branched annual with pinkish flower heads surrounded by 2cm long straw-coloured spiny bracts and greyish, pinnately-divided leaves. A native of Europe, it has been found occasionally in the Metropolitan area, flowering in summer.

Centaurea melitensis , PH

Chondrilla juncea (skeleton weed) DP is a serious crop weed and potential threat to large areas of the wheatbelt but has been prevented from establishing large populations in Western Australia by a sustained eradication effort. It occurs in the wheatbelt and occasionally in the Metropolitan area. If found, it should be reported to Agriculture Western Australia. It is a perennial that grows as a flat rosette of oblong, deeply-toothed leaves in winter and spring, followed by a wiry, much-branched flowering stem (up to 1m high) in spring. The small, yellow heads are either terminal or lateral, solitary or in groups of up to five, and are produced from December to May, though mostly in summer. All plant parts exude copious white latex. A native of the Mediterranean and eastern Asia.

Chondrilla juncea , RR

Chrysanthemoides monilifera (boneseed, bitou bush) DP is an erect shrub to 3m with dull green elliptic leaves and showy flower heads with yellow ray florets. Planted in gardens, it is an aggressive coloniser, especially of sand dune areas. Although subject to eradication efforts, it has been found occasionally near Geraldton, Wyalkatchem, Narrogin, Perth and Busselton. Native to South Africa.

Chrysanthemoides monilifera , RR

Asteraceae continued

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*Argyranthemum* is a genus of 22 species native to Madeira and the CanaryIslands. Two species, both garden escapes, have been recorded as naturalised on limestone cliffs on the Swan River estuary. *A. foeniculaceum* (Tenerife daisy) is a stout branching perennial to 1m tall. It has greyish, feathery, divided leaves and the 5cm wide flowers with white ray florets are produced in summer. *A. frutescens* (marguerite) is a more delicate branching perennial that is winter-flowering, with smaller white flowers (3cm) and bright green leaves. *Aster subulatus* (bushy starwort) is a common plant in wetlands, wetter wasteland and roadside drains from Gingin to Albany. It is a summer-growing, dark green, spindly, erect annual or biennial to 1.5m, with small leaves closely apressed to the stem. The heads are small, with inconspicuous white or blue ray florets. Native to North America.	*Aster subulatus* , PH
*Berkheya rigida* (African thistle) DP is a prickly perennial to 60cm tall, that often forms colonies by rooting at the nodes. The leaves, and the bracts below the flower heads, are stiff and prickly, but the stem does not bear prickles. The flowers are yellow and are produced from late spring to autumn. Currently found only in coastal areas near Augusta, and thought to have been introduced from South Africa in ballast from ships involved in the early timber trade.	*Berkheya rigida* , GK
*Bidens* is found worldwide, with two species naturalised in Western Australia. Both are erect annual herbs with four-angled stems, heads in terminal panicles and narrow black fruits with barbed awns at one end. *B. bipinnata* (beggar's ticks) has deeply lobed, bipinnate leaves, two to three awns and usually no ray florets. It occurs at Kalbarri, Newman and in the Kimberley. *B. pilosa* (cobbler's pegs) has pinnate leaves, three to four awns and white or cream coloured ray florets. It is found in the Pilbara and Kimberley. Both favour wetlands, flower in autumn, and are thought to be spread by cattle.	*Bidens pilosa* , RR
*Carduus* (thistles) are annuals or biennials with prickly, winged stems, flowering in spring and early summer, that are found as weeds of pasture, wasteland and disturbed bushland in the south-west. Their seeds are carried on a parachute of simple hairs (unlike Cirsium, the spear thistles, that have a feathery parachute). There are about 120 species in Europe, Asia and North Africa, and three have become naturalised in Western Australia. *C. nutans* (nodding thistle), once found at Green Range near Albany, has now been eradicated. The bracts under the head in this species are often strongly recurved. *C. pycnocephalus* (slender thistle) has prickly wings on the stems that become discontinuous as they get nearer the flower heads, which are usually in clusters of two or three. Each head is cylindrical, up to 1.5cm across, with reddish-purple flowers. It is a common weed of agricultural areas and disturbed bushland from Perth to Esperance. *C. tenuiflorus* (sheep thistle) is very similar to slender thistle, but the prickly wings on the stem extend right up to the flower heads and the plant is somewhat stouter. Found in agricultural areas and peppermint woodland.	*Carduus* *pycnocephalus* , RR
*Carthamus lanatus* (saffron thistle) DP is an annual from southern Europe that grows to 70cm. The leaves are rigid, with spiny lobes. The yellow flower heads are surrounded by spiny bracts and are borne in terminal clusters. It flowers in spring and summer and is a serious weed of agricultural and pastoral areas as well as disturbed bushland throughout the south-west. Two other species have occasionally been recorded as agricultural weeds in Western Australia, *C. leucocaulos* (glaucous star thistle) DP that has purplish florets and *C. tinctorius* (safflower) which is similar to saffron thistle except for having undivided leaves and darker gold flowers. It is sometimes grown as an oil-seed crop and is an escape from cultivation.	*Carthamus lanatus* , RR
*Centaurea* is a cosmopolitan genus of about 600 species, of which three have become naturalised in Western Australia. The commonest and most widespread is *C. melitensis* (Maltese cockspur) that occurs from Carnarvon through to the arid zone and across the Nullarbor. It is an erect biennial to 80cm with lobed leaves and yellow, thistle-like flower heads borne terminally or on short branches in the upper axils. The bracts below the heads have a short, often reddish spine. The stems have non-prickly wings. It flowers in spring and summer and is originally from the Mediterranean. *C. solstitialis* (St Barnaby's thistle) is a similar plant, also with yellow flower heads, but the bracts have a long yellow spine. The leaves and stem are grey-woolly. It is found principally on the Nullarbor and in the eastern wheatbelt, flowering in summer. *C. calcitrapa* (star thistle) is a much-branched annual with pinkish flower heads surrounded by 2cm long straw-coloured spiny bracts and greyish, pinnately-divided leaves. A native of Europe, it has been found occasionally in the Metropolitan area, flowering in summer.	*Centaurea* *melitensis* , PH
*Chondrilla juncea* (skeleton weed) DP is a serious crop weed and potential threat to large areas of the wheatbelt but has been prevented from establishing large populations in Western Australia by a sustained eradication effort. It occurs in the wheatbelt and occasionally in the Metropolitan area. If found, it should be reported to Agriculture Western Australia. It is a perennial that grows as a flat rosette of oblong, deeply-toothed leaves in winter and spring, followed by a wiry, much-branched flowering stem (up to 1m high) in spring. The small, yellow heads are either terminal or lateral, solitary or in groups of up to five, and are produced from December to May, though mostly in summer. All plant parts exude copious white latex. A native of the Mediterranean and eastern Asia.	*Chondrilla juncea* , RR
*Chrysanthemoides monilifera* (boneseed, bitou bush) DP is an erect shrub to 3m with dull green elliptic leaves and showy flower heads with yellow ray florets. Planted in gardens, it is an aggressive coloniser, especially of sand dune areas. Although subject to eradication efforts, it has been found occasionally near Geraldton, Wyalkatchem, Narrogin, Perth and Busselton. Native to South Africa.	*Chrysanthemoides monilifera* , RR