226. COMPOSITAE 567 



229. Involucral bracts in two rows. Corolla of the hermaphrodite (male) 



flowers 4-toothed. Anthers entire at the base. Fruits compressed, 



glabrous. (See 216.) Cotula L. 



Involucral bracts in 3 or more rows. Corolla of the hermaphrodite 

 (male) flowers 5-toothed. Anthers arrow-shaped. Fruits nearly terete, 

 hairy. — Species 2. Central Africa .... Adelostigma Steetz 



230. Corolla of the female marginal flowers yellow, thread- or sliortiy strap- 



shaped. Fruits scarcely compressed, 3 — 6-ribbed. Shrubs. Heads 

 in corymbs. — Species 40. Tropics. Some arc used as pot-herbs. 



Psiadia J acq. 



Corolla of the female marginal flowers white red or blue, strap-shaped. 



Fruits compressed 231 



231. Stem woody, at least at the base. Marginal flowers in i — 2 rows. Pappus- 



bristles usually in one row. — Species 65. South and Central Africa. 



Some are used as ornamental plants. (Including Asterosperma Less., 



Detris Adans., and Diplopappus DC, under Aster L.) Felicia Cass. 



Stem herbaceous 232 



232. Involucral bracts in 2 rows, membranous. Marginal flowers usually in 



several rows, with a linear corolla. Style-branches with a mostly short 

 triangular appendage. Pappus-bristles usually in one row. — Species 

 13, one of them only naturalized. Several species are used medicinally. 



Erigeron L. 

 Involucral bracts in 3 or more rows. Marginal flowers in 1^2 rows, 

 with a usually oblong corolla. Style-branches with a lanceolate ap- 

 pendage. Pappus-bristles in two rows. — Species 10. South and 

 North Africa. Some are used as ornamental or medicinal plants, 

 (Including Linosyris Cass.) Aster L. 



233. (223.) Involucral bracts in several rows. (See 232.) . . . Aster L. 

 Involucral bracts in one row, but sometimes surrounded by some much 



smaller ones 234 



234. Heads of two kinds, some with most of the flowers hermaphrodite (male), 



the others with most of them female. Corolla red or white ; limb short- 

 ly strap-shaped in the female flowers. Herbs. Leaves radical, broad. 

 Heads in racemes or corymbs. — Species i. North Africa. Used as 



an ornamental plant Petasites Gaertn. 



Heads all alike 235 



235. Female marginal flowers in several rows. Corolla yellow ; limb long 



strap-shaped in the female flowers. Herbs. Leaves radical, broad. 

 Heads solitary. — Species I. North Africa. Used medirinallv. "Colts- 

 foot." Tussilago L. 



Female marginal flowers in one row 236 



236. Inner fruits without a pappus, outer with a pappus of interwoven hairs. 



Style 2-cleft. Herbs. Leaves pinnately divided. Heads solitary. — 



Species 3. South Africa Ruckeria DC. 



Inner and outer fruits with a pappus of bristles 237 



