332 SYNGENESIA POLYGAMIA FRUSTRANEA. [CL. XIX. 



abrupt; seed-down none. Receptacle narrow, covered with 

 lance-shaped, chaffy scales. Named after Achilles. 406. 



1. A. Ptdrmica. Sneeze-wort. Goose-tongue. Leaves narrow, lance- 

 shaped, pointed, acutely serrate, smooth. Stem simple, erect, from 



six inches to two feet high, terminating in a large, nearly simple 

 corymb, with white flowers: leaves very minutely, acutely, doubly 

 serrated. Perennial : flowers from the middle of July to the end of 

 September: grows in moist pastures, by ditches, and at the edges of 

 corn-fields : not uncommon. Eng. Bot. vol. xi. pi. 757. Eng. Fl. 

 yol. iii. p. 460. 1219. 



2. A. serrdta. Serrated Yarrow. Leaves narrow lanceolate, sessile, 

 downy, deeply serrate, laciniate at the base ; flowers almost simply 



corymbose. Stem simple, erect, downy, about eighteen inches high, 



terminating in a simple or slightly branched corymb of yellowish flowers, 

 much inferior in size to those of the last species, of which, however, it is 

 probably a mere variety. Perennial: flowers in August: found near 

 Matlock, Derbyshire, by Mr. Rupp and Mr. Williams. Eng. Rot. 

 vol. xxxvi. pi. 2531. Eng. FL vol. iii. p. 461. 1220. 



3. A. Millefolium. Common Yarrow, or Milfoil. Leaves twice pinnate, 

 with lance-shaped, pointed segments, hairy on the back ; stems fur- 

 rowed. Stems commonly decumbent at the base, then erect, about 



a foot high, terminating in a dense, often-divided corymb, with white 

 or purplish flowers. Perennial : flowers from the middle of June to the 

 end of October : grows on banks, by road-sides, and in dry pastures : 

 common. Eng. Bot. vol. xi. pi. 758. Eng. FL. vol. iii. p. 462. 1221. 



4. A. tomentosa. Woolly Yellow Milfoil, or Yarrow. Leaves twice 

 pinnatifid, with linear, acute, crowded segments ; corymbs repeatedly 



compound. Stems about a foot high, decumbent at the base, then 



erect, terminating an often-divided corymb of yellow flowers. Peren- 

 nial : flowers in July and August: on Spittle Hill, Dumbartonshire, 

 and on hills near Paisley, discovered by Mr. Hugh Ross : also in 

 Ireland. Eng. Ft. vol. iii. p. 462. Eng. Bot. pi. 2532. 1222. 



POLYGAMIA FRUSTRANEA. 



42. CENTAURE'A. CENTAURY. KNAPWEED. 



Common calyx roundish, closely imbricated, with scales of 

 various forms. Compound corolla of numerous tubular florets ; 

 those of the disk perfect, regular, with five equal, spreading 

 segments, an oblong limb, and a slender tube ; those of the ray 

 fewer, with a rudimentary pistil, not perfecting seed, spreading, 

 often wanting, funnel-shaped, with five or more unequal seg- 

 ments. Filaments hair-like, very short; anthers united into a 

 cylindrical tube. Germen small, oblong. Style thread-shaped, 

 about the length of the stamens ; stigma blunt, often cleft, pro- 

 minent. Style and stigma very small in the florets of the ray. 

 Seed in the disk only, of various forms ; seed-down various, or 

 wanting. Receptacle bristly. Named after the Centaur Chiron. 



407. 



