290 COMPOSITE. TUBULIFLOR^. 



D. sylvestris Mill. Diet. Stems stout, £-5 feet high prickly : lanceo- 

 late-oblong, connate at base, 4-6 inches long: involucre as long as the 

 heads : bracts of the receptacle tipped with a long and straight flexible 

 awn; corolla flesh-color. In waste places and old fields. Naturalized 

 from Europe. 



Order LI. COMPOSITE Vaill. Act, Acad. Paris 143. 



Herbs, shrubs or small trees with various leaves and small 

 flowers in dense, closely involucrate heads on a simple recepta- 

 cle, the heads often resembling a single flower. Flowers 5- 

 merous or sometimes 4-merous. Tube of the calyx wholly ad- 

 nate to the ovary, its limb none or obsolete or developed into 

 a cup or teeth scales awns or capillary bristles. Corolla epigy- 

 nous, valvate in the bud. Stamens as many as lobes of the co- 

 rolla and alternate with them, inserted on the corolla-tube: 

 anthers united by their edges into a tube . commonly with ster- 

 ile tips or appendages, the cells introrse, discharging the 

 pollen within the tube, this forced out by the lengthening of 

 the style. Style in all fertile flowers 2-cleft or lobed at sum- 

 mit and bearing introrse -marginal stigmas; ovary 1 -celled, 

 with a solitary anatropous ovulfe erect from the base. Fruit an 

 achene. Seed with a straight embryo and no albumen. 



Herbs are said to be homogamous when all its flowers are alike 

 in sex ; heterogamons when unlike (generally marginal flowers 

 pistillate or neutral, and central hermaphrodite or by abortion 

 only staminate) : androgynous when of pistillate and staminate 

 flowers : monoecious or dioecious when the floAvers of different sexes 

 are in different heads either on the same or different plants: ra- 

 diate when there are enlarged ligulate flowers in the margin : 

 ligulate when all the flowers have ligulate corollas: discoid when 

 there are no enlarged marginal corollas. 



Suborder I. TUBULIFLOR^. 



Herbs or hhrubs with watery or resinous, rarely somewhat 

 milky juice. Corollas tubular and regular in all the hermaphro- 

 dite flowers. 



* Heads homogamous and discoid flowers all hermaphrodite, never 

 yellow; anthers not caudate at base. 



I. Eupatoriace*. Style-branches elongated, more or less clavate-thiek- 

 ened upward and obtuse, minutely papillose-puberulent, stigmatic only 

 below the middle. 



* * Heads homogamous or heterogamons; flowers not rarely yellow: 

 style-branches of hermaphrodite flowers with stigmatic lines mostly 

 prominulous and extending either to the naked summit or to a more or 

 less distinct pubescent or hispidulous tip or appendage. 



II. Asteroidere. Anthers not cordate at base ; style-branches in her- 

 maphrodite flowers flattened and with a distinct terminal appendage : 

 disk corollas generally yellow : rays of same or different color. 



