CLASSIFICATION OF ANGIOSPERMS. 393 



which are rugose, and pubescent on the under surface. The leaves 

 and flowers are official (p. 625). 



Grindelia species. — The plants are perennial, greenish-yellow, 

 resinous herbs, sometimes being under-shrubs, with alternate, 

 sessile or clasping, oblong to lanceolate, spinulose-dentate leaves, 

 and large, terminal, yellowish heads, consisting of both ligulate 

 and tubular flowers. The leaves and flowering tops of Grindelia 

 robusta and G. squarrosa are official (p. 626). 



Erigeron canadensis {Leptilon canadense) (Canada fleabane) 

 is an annual or biennial, hispid-pubescent herb found growing in 

 fields and waste places in nearly all parts of the world. The 

 stems are simple, with numerous crowded leaves and numerous 

 flowers occurring in terminal panicles. The plants are sometimes 

 branched and i to 3 M. high. The leaves are linear, nearly 

 entire, of a pale green color, the lower and basal ones being spat- 

 ulate, petiolate and dentate or incised. The flowers are white and 

 the heads are composed of both ligulate and tubular florets, the 

 former being pistillate and not longer than the diameter of the 

 disk. The pappus consists of numerous capillary bristles and 

 the involucre, which is campanulate, consists of five or six series 

 of narrow, erect bracts. The fresh flowering herb contains 0.3 

 to 0.4 per cent, of a volatile oil which is official, tannin, and a 

 small amount of gallic acid. The oil is obtained by distillation 

 and consists chiefly of d-limonene. 



The genus Erigeron includes a number of species which have 

 medicinal properties. E. annuus (Sweet scabious or Daisy flea- 

 bane) is a low, branching, annual herb, characterized by its linear- 

 lanceolate or ovate-lanceolate leaves and its conspicuous flowers, 

 which resemble those of the common daisy, the ray-flowers often 

 being tinged with purple (Fig. 181). It contains a volatile oil 

 resembling that of Canada fleabane, and tannin. The Philadel- 

 phia fleabane {Erigeron philadelphicus) is a perennial herb pro- 

 ducing stolons, and has clasping or cordate leaves, the basal being 

 spatulate, and is further distinguished by its light purplish-red 

 ray-flowers. 



Anthemis nobilis (Roman chamomile) is an annual or peren- 

 nial, procumbent, branched herb, with numerous 2- to ^-pinnately 

 divided leaves, the ultimate segments being narrow-linear. The 



