118 THE WEEDS OF NEW SOUTH WALES. 



St. Barnaby's Thistle (Centaurea solstitialis L.). 

 (COMPOSITE: Thistle Family.) 



Popular Description. An annual plant, with a yellow, prickly thistle-like- 

 flower; the whole plant covered with a short whitish cottony covering; the 

 lower or radical leaves dissected, the terminal lobe larger than the lower 

 ones, and the upper ones linear, with wavy edges. 



Botanical Description, 



Stem near 2 feet high, alternately branched, winged from the decurrent 

 leaves, which are lanceolate and entire, slightly waved ; the radical leaves are 

 4 or 5 inches long, lyrate, the lobes alternate, acute, the terminal one large, and 

 more or less triangular. Flowers solitary at the end of each branch, bright 

 yellow. Scales of the calyx tipped with palinated yellowish spines, of which 

 the central one is very long, strong, and different from the rest. The whole 

 herb is harsh and rigid, but clothed with a cotton-like web (as is the calyx), 

 somewhat viscid, and intensely bitter. Sowerby's " English Botany," xii, t. 

 243. 



Allied Thistles. We have already figured and described two Centaur eas, 

 viz., C. calcitrapa, the other ordinary Star Thistle (see* page 110), and 

 C. melitensis, the Cockspur (see page 114). The former is pink-flowered, 

 and the latter is yellow-flowered like the weed now under description. 



Comparing the two yellow thistles, Bentham says that " C. solstitialis i& 

 an annual, with the habit, foliage and yellow florets of C. melitensis, but 

 with a much longer and stouter spine to the intermediate involucral bracts, 

 while the inner ones have a jagged scarious appendage without any spine.' r 



Names. Sowerby wrote in his " English Botany " considerably over a 

 century ago, "It flowers about midsummer, whence the name, but lasts till 

 late in autumn, and in the south of Europe even till December." The name- 

 referred to is St. Barnaby's Thistle (apostle and saint), and his day is llth 

 June, which explains the reference to midsummer. 



"Yellow Thistle" or "Yellow Star Thistle" which it shares with C. 

 melitensis. 



Where found. It is a native of Europe, North America, and Western 

 Asia. It has become extensively distributed in Australia, having been 

 recorded from practically every State. In New South Wales it is 

 widely diffused. Western localities are E-ichmond and Bathurst; southern 

 ones, Burrinjuck and Queanbeyan; but it doubtless occurs far beyond these 

 boundaries. A correspondent from Tamworth in January, 1917, wrote : " I 

 saw only a very few plants of it until to-day, when I saw a paddock very 

 badly infested." 



As a rule it is looked upon as a weed pure and simple, and the advice is- 

 given to eradicate it when it is in flower, as it is an annual and must not be 

 allowed to seed. The following paragraph will give food for thought. 



