Order TO.— ASTERWORTS. 



229 



8 C. latifo'lia. Stem 4-Gf. liigh. Eiiys entire. Leaves ovate, serrate. S. 

 I) C auricula'ia. Stem l-3f. high. Eays 2-5-toothecl. Lvs. often eared at base. S. 

 10 C. lanceola'ta. Stem 2-of. high. Euys 4-5-toothed. Lvs. lanceolate, entire. S. 

 n C. senifo'lia. Leaf divisions all entire, appearing in 6-leaved whorls. S. 



12 C. verticilla'ta. Leaf divisions all again divided into narrow-linear lobes. \V. 



13 C. palma'ta. Lvs, deeply 3-eleft, wedge-shaped, lobes linear, not whorled. W. 



14 C. delphinifo'lia. Leaves sessile, 3-parted, the divisions often lobed. S. 



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



olate, sometimes divided. Stem round. S. 



16 C. angustifo'lia. Karrow-lv. G. Leaves petioled, 



narrow-spatulate, entire. Stem square. S. 



17 C. CEm'leri. (Einler''s G. Leaves petioled, lance- 



ovate, entire. Stem round below. S. 

 13 O. Drummon'dii. Drummond''8 G. Lvs. pin- 



nately 3-5-foliate, divisions oblong- oval, 



entire, f 

 19 C. tincto'ria. Byer'^s G. Leaves pinnatcly 



much divided, divisions linear, entire, t 



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



linear, entire. Eays rose-white. E. 



21 0. nuda'ta. Leafless G. Stem few-leaved, leaves 



awl-shaped, entire. Rays 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 11 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 yelloAv. — The spe- 

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



* Eadical 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 i' . . .3, 4 

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



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



c Involucro scales with searious margins or wholly scarious. . . .f 



