70 



NOTES ON " THE CALIFORNIAN THISTLE." 

 By W. Archer, F.L.S. 



The genus Carduus, as established by Liniia3us, consists of 

 what are called " True Thistles," with a hairy pappus or calyx ; 

 "Plume Thistles," with a feathery pappus or calyx. 



Bentham, in his " Hand-book of the British Flora," follows 

 Linnaeus ; but some botanists class the " True thistles " under 

 the genus ' Carduus' and the " Plume thistles " under the 

 genus Cnicus or Clrsium. 



The " Milk Thistle " (Carduus Ilarianus) represents the 

 " true thistles " in Tasmania, and the Carduus lanceolatus^ or 

 " Spear Thistle " (Cnicus lanceolaius, of " The British Flora," 

 by Hooker and Arnott), the Plume Thistles. The " Spear This- 

 tle " of England is what is called in Tasmania " The Scotch 

 Thistle ;" but it is not by any means peculiar to Scotland. 

 (The Scotch heraldic thistle is the Onopordon acantMwni, 

 which is a native of central Europe and of Asia, but certainly 

 not a native of Scotland, according to Bentham.) The " Spear 

 Thistle " (Carduus or Cnicus lanceolatus) has a biennial root- 

 stock, which sends up for two years, (after which it dies), 

 annual stems, winged and prickly, with broadish, pinnatifid, 

 prickly -lobed leaves, and large, egg-shaped flower -heads, 

 enveloped in involucral, spreading bracts, with stiif, largish 

 prickles. The " Creeping Thistle " (Carduus or Cnicus arven- 

 sis) has a perennial and creeping root-stock, which sends up, 

 perpetually, annual stems, with rather narrow, pinnatifid, very 

 prickly-lobed leaves, and dioecious flower-heads {i.e., the males 

 on one plant and the females on another), — the male flower- 

 heads nearly globular, and the female flower-heads egg-shaped, 

 enveloped in involucral, appressed bracts, with small prickles. 



Both the Spear Thistle and the Creeping Thistle are found 

 abundantly in Europe and Asia. The Spear Thistle is, of 

 course, the more easily destroyed of the two. The Creeping 

 Thistle seems to be quite ineradicable. 



The Creeping Thistle is mentioned by Professor Johnston 

 as being called in the United States of America the " Cana- 

 dian Thistle," — probably because it travelled thither from 

 Canada ; and so, I suppose, the same thistle is called here the 

 *' Californian Thistle " because it has come to us from Cali- 

 fornia. It is nevertheless the " Creeping Thistle " of Great 

 Britain, — and it never quits a country into which it has been 

 introduced. 



