COMPOUND FLOWERS 151 



II. CYNAROCEPHALiE. Thistle Group 



14. Arctium (Bur-clock). Involucre globose, scales ending in 

 hooked points ; receptacle chaffy ; fruit oblong, 4-sided ; pappus 

 short. (Name from the Greek, arclos, a bear, from the roughness 

 of the heads of flowers.) 



15. Serratula (Saw-wort). Stamens and pistils on different 

 plants ; involucre imbricated, scales not prickly ; receptacle chaffy 

 or bristly ; fruit flattened, not beaked ; pappus hairy. (Name 

 from the Latin, serrula, a little saw, the leaves being finely serrated.) 



16. Saussurea. Involucre imbricated, scales not prickly; 

 anthers bristly at the base ; receptacle chaffy ; pappus double, 

 outer bristly, inner longer, feathery. (Named in honour of the two 

 Saussures, eminent botanists.) 



17. Carduus (Thistle). Involucre swollen below, imbricated 

 with thorn-like scales ; receptacle bristly ; pappus hairy, united 

 by a ring at the base, and soon falling off. (The Latin name of 

 the plant.) 



18. Cnicus (Plume-thistle). Resembling Carduus, except that 

 the pappus is feathery. (Name from the Greek, cnizo, to prick.) 



19. Onopordium (Cotton-thistle). Receptacle honeycombed; 

 fruit 4-angled ; pappus hairy, rough ; in other respects resembling 

 Carduus. (Name of Greek origin.) 



20. Carlina (Carline-thistle). Resembling Cnicus, except that 

 the inner scales of the involucre are chaffy and coloured, and spread 

 like a ray. (Name, the same as Carolina, from a tradition that the 

 root of one species, C. acaulis, was shown by an angel to Charle- 

 magne as a remedy for the plague which prevailed in his army.) 



21. Centaurea (Knap-weed, Bluebottle, etc). Involucre imbri- 

 cated ; receptacle bristly ; pappus hairy, or ; outer florets large, 

 irregular, destitute of stamens and pistils. (Name from the Centaur 

 Chiron, who is fabled to have healed wounds with it.) 



III. Tubiflor.e. Tansy Group 



22. Bidens (Bur-marigold). Fruit crowned with 2 or 3 erect, 

 rigid bristles, which are rough, with minute teeth pointing down- 

 wards. (Name from the Latin, bis, double, and dens, a tooth, from 

 the structure of the fruit.) 



23. Eupatorium (Hemp-agrimony). Heads few-flowered ; in- 

 volucre imbricated, oblong ; receptacle naked ; styles much longer 

 than the florets. (Name from Mithridates Eupator, who is said to 

 havp brought the plant into use.) 



