264 Composite? Echinops. 



40. ECHlNOPS. 



Herbs of Thistle- like aspect remarkable for having the capi- 

 tules 1 -flowered in terminal clusters, resembling the flower- 

 heads of many other genera. Florets white or blue, with an 

 involucre of prickly scales and bristles. The cluster of heads 

 or capitules is surrounded by an involucre of linear scales, thus 

 completing the appearance of a single head. The species are 

 chiefly from the Mediterranean region. The name is from SALVOS, 

 a hedgehog, and 6S|rty, resemblance. They are commonly 

 known as Grlobe Thistles. 



1. E. Rutkenicus (fig. 148). Perennial rising to a height 

 of 2 or 3 feet. Florets blue. A native of Germany, flowering 

 all the Summer. 



2. E. RUro. Very near the foregoing, with pinnatifid 

 not spinescent leaves, downy beneath, and webbed above. 

 South of Europe. 



3. E. cornigerus. This has very spiny silvery foliage and 

 large white flower-heads. Central Asia. 



4. E. sphcerocephalus. A taller plant attaining a height of 

 5 or 6 feet. Leaves large, pinnatifid, clothed with a cottony 

 down beneath. Flower-heads very numerous, blue. South of 

 Europe. 



41. XERAISTHEMUM. 



Annuals from the Mediterranean region having the coloured 

 radiating scarious involucral bracts of the Everlastings, and 

 employed for the same purposes ; but the other characters are 

 those of the Thistle tribe. Eeceptacle paleaceous, pappus 

 bristly. Outer involucral bracts brown, small, scaly, imbri- 

 cated. The name indicates the nature of the flower-heads, 

 being a compound of f^os, dry, and avOepov, flower. 



1. X. dnnuum. A branching plant from 1 to 2 feet high, 

 with linear cottony leaves and solitary terminal purple, pink or 

 white flower-heads on long peduncles. 



42. CENTAtTREA. 



A large genus of annual and perennial herbs of very diverse 

 habit. Involucre globose or oblong; bracts imbricated, scarious, 

 fringed, toothed, or spinous. Receptacle bristly. Florets all 

 tubular, the outer ones often larger and neuter ; lobes 5, narrow. 

 Achene flattened ; pappus short and bristly, rarely none. There 

 are upwards of 200 species, the greater part of which inhabit 



