YARROW AND SNEEZE WORT. 



45 



carefully extirpated, by the meadow being grazed for three 

 or four years to prevent the seeding:, and by cutting with the 

 scythe any plants that may escape the bite of the grazing 

 animals, and shoot up the seed stems. The root is annual, 

 or at most biennial. 



7. " Yarrow and sneeze wort," or the " Achillese" of botany, 

 are common plants on some dry warm pastures. The plant 

 belongs to the class and order " Syngenesia polygamia super- 

 flua," of Linneus, and the natural order " Corymbiferse" of 

 Jussieu. 



Generic character, — Calyx common ovate, imbricate; 

 scales ovate, acute, converging. Corolla compound, radiate ; 

 coroUets hermaphrodite, tubular in the disk. Females hgu- 

 late, five to ten in the ray. Proper of the hermaphrodite, 

 funnel-shaped, five-cleft, spreading. Female obcordate, 

 spreading, trifid ; the middle cleft less than the others. Sta- 

 mina in the hermaphrodites : filaments five, capillary very 

 short ; antheree cylindrical, tubular. Pistil in the her- 

 maphrodites : germ small ; style filiform, the length of the 

 stamens ; stigma obtuse, emarginate. In the females germ 

 small ; style fihform, the same lenp th as in the others ; stig- 

 mas two, obtuse, reflex. Pericarp none. Calyx scarcely 

 changed ; receptacle filiform, elongate as the disk of the seeds; 

 ovate twice the length of the calyx. Seeds sohtary, ovate, 

 furnished with flocks ; but having no down. Kecepta- 

 cle chaffy, elevated-chaffs, lanceolate the length of the 

 florets. 



Essential character. — Calyx ovate, imbricate ; florets of 

 the ray about four ; down none. Receptacle chaffy. 



Most of the plants of this genus are hardy, herbaceous, 

 fibrous-rooted perennials, with the flowers commonly in 

 corymbs at the ends of the stalk and branches ; the ray in 

 some yellow, in others white, in a few purple ; the leaves in 

 many of the species are pinnate, bipinnate, or superdecom- 

 pound ; in a few they are simple. Only two species are na- 

 tives of Britain, the " Achillea millefolium," the common yar- 

 row, and the ^'Achillea Ptarmica," or sneeze wort. The 

 former has the leaves bipinnate, naked ; divisions linear, 

 toothed. Stems furrowed towards the top. It flowers from 



