BOTANY. ' 135 



amounts to upwards of 1000, including 9500 species, and forming about 

 one tenth of all the known species. Various subdivisions have been 

 proposed by different authors ; those by Linnaeus into Polygamia sequalis, 

 superflua, frustranea, necessaria, and segregata, will be found explained on 

 page 54. The sub-orders more usually followed by modern authors are 

 those of De Candolle, as follows : 1. Tubulißorce. Corolla of the perfect 

 flowers tubular, and regularly five- (rarely three- to four-) lobed or toothed. 

 2. Labiatifloj'ce. Corolla of the perfect flower bilabiate. 3. Liguliflorce. 

 Flowers all perfect and ligulate. (The genera marked with an asterisk 

 are North American.) 



Sub-order 1. Tubuliflor^. 



Tribe 1. VernoniacecE. Style of the perfect flowers cylindraceous ; the 

 branches usually elongated and subulate, hispid throughout ; the stigmatic 

 lines not extending beyond their middle. 



Sub-tribe 1. Vernonicce. Heads discoid, homogamous. Division 1. 

 Euvernoniece. a, Ethulieae. Example : Ethulia. b, Heterocomeae. Examples : 

 *Stokesia, *Vernonia. c, Albertinieae. Example : Albertinia. Division 2. 

 *ElephantopecB. Example : Elephantopus. Division 3. RolandrecB. 

 Example : Gundelia. Division 4. BojeriecB. Example : Synchodendron. 



Sub-tribe 2. Pectidece. Heads radiate, heterogamous. Division 1. Liabece. 

 Example : *Xanthisma. Division 2. Eupectidece. Examples : *Pectis, 

 Pectidopsis. 



Tribe 2. Eupatoriacecc. Style of the perfect flowers cylindraceous : 

 the branches elongated, obtuse, or clavate, externally puberulent or papillose 

 towards the summit, the stigmatic lines obscure, terminatins; near their 

 middle. , 



Sub-tribel. EupatoriecB. Heads discoid, homogamous. Division!. Alo7nie<c. 

 Ex. : Orsinia. Division 2. Ageratece. Ex. : *Coelestina, * Ageratum, *Sclero- 

 lepsis. Division 3. Adenostylece. Ex. : *Liatris, *Kuniii, *Eupatorium. 



Sub-tribe 2. Tussilaginece. Heads with the flowers heterogamous or 

 dioecious. Division 1. PetasitecB. Examples: *Nardosmin, *Adenocaulon. 

 Division 2. EutussilaginecB. Example : *Tussilago. 



Tribe 3. Asteroidece. Style of the perfect flowers cylindraceous : the 

 branches linear, externally flattish, minutely and equally pubescent above, 

 stigmatic lines prominent, extending about to the origin of the exterior 

 pubescence. 



Sub-tribe 1. Asterinece. Heads heterogamous and radiate, or homo- 

 gamous. Receptacle seldom chafly. Anthers not caudate. Leaves 

 alternate. Division 1. Amelliece. a, Euamelleae. Example: Amellus. h, 

 Heterothalameae. Example : Heterothalamus. Division 2. Asterece. a, 

 Euastereee. Examples : *Galatella, *Aster. b, Diplopappea?. Example : 

 *Diplopappus. c, Erigerese. Example : *Erigeron. d, Heteropappeae. 

 Examples : *Cha3topappa, *Boltonia. e, Bellieae. Example : BeHium. /' 

 Bellideae. Examples : *Bellis, *Aphanostephus. Division 3. Chrysocome(/!. 

 Ö, Gymnospermeae. Example: *Gymnosperma. /;, Achyrideoe. Example: 

 *Amphiachyris. c, Heterothecae. Exam})le: *Bradburia. d, Psiadieae, 

 Erato. e, Chrysopsideae. Example : Chrysopsis. /, Solidagineae 



1.3") 



