240 



THE FLORA. 



8 O. latifo'lia. Stem 4-Gf. high. Kays entire. Leaves ovate, serrate. 8. 



9 C auricnla'ta. Stem l-3f. high. Kays 2-5-toothed. Lvs. often eared at base. 8 



10 C lanceola'ta. Stem 2-8f. high. Rays 4-5-toothed. Lvs. lanceolate, entire. 8. 



]1O seni/o'lia. Leaf divisions all entire, appearing in 6-leaved whorls. S. 



12 O. verticilla'ta. Leaf divisions all again divided into narrow-linear lobes. W. 



13 O. palma'ta. Lvs. deeply 8-cleft, wedge-shaped, lobes linear, not whorled. W. 

 M O. delphinifo'lia. Leaves sessile, 3-parted, the divisions often lobed. S. 



15 O. gladia'ta. Sword-lv. C. Leaves petioled, lance- 



olate, sometimes divided. Stem round. S. 

 1 O. angustifo'lia. Narroiv-lv. O. Leaves petioled, 



narrow-spatulate, entire. Stem square. S. 

 7 O. CEm'leri. (Euiler'' C. Leaves petioled, lance- 

 ovate, entire. Stem round below. S. 



18 O. Drummon'dii. Drummond 's C. Lvs. pin- 



nately 3-5-foliate, divisions oblong oval, 

 entire, t 



19 O. tincto'ria. Dyer's O. Leaves pinnately 



much divided, divisions linear, entire, t 

 20 C. ro'sea. Rose G. Stem leafy, leaves narrow- 



linear, entire. Rays rose-white. E. 

 l O. nnda'ta. Leafless 0. Stem few-leaved, leaves 



awl-shaped, entire. Kays rose-red. S. 



5. ASTER. Starwort 

 Heads many-flowered. Scales of the invo- 

 lucre generally imbricated in two or more 

 rows, and with green tips. Disk florets tubu- 

 lar, perfect, rays fertile, in one row, oblong, 

 revolute when old. Receptacle flat, marked 

 with pits. Pappus simple, hair-like, rough. Achenium usually flattened. 

 A large genus of V. herbs, very abundant in the United States, flower- 

 ing in late summer and autumn. Leaves alternate ; disk florets yellow, 

 changing to purple ; rays blue, purple, or white, never yellow. The spe- 

 cies are very variable, and many of them are hard to distinguish. 



* Radical and lower leaves cordate and petiolate ---- a 



Radical leaves never cordate ---- c 



a Heads in loose corymbs. Rays white or whitish ... .1, 2 



a Heads in racemes or panicles, blue or bluish. . . .b 



b Leaves evidently serrate ; rays light blue, about 12, spreading f . . .3, 4 

 b Leaves entire or nearly so ; rays bright blue, spreading near 1'. . . .5-7 



c Involucre scales tipped with green, or the outer ones wholly green. . . .d 



o Involucre scales with scarious margins or wholly scarion8....f 



Fig - 524 Asler lsevis - 



