CXXIT. COMPOSITE. 497 



pentagonal areolae, that' enclose the bases of tlie flowers. Involtjorb {peri- 

 clinium) composed of one or many series of bracts {scales or leaflets), sometimes 

 furnisliecl outside with accessory bracts {calycuU). Flowers g , or $ or ^ or neuter, 

 sometimes all 5 in one capitulum ; sometimes ? , or neuter at the circumference, 

 the inner S ; sometimes $ at the centre^ and ? at the circumference; capitula 

 sometimes exclusively composed of ? or <? flowers, and then monoecious or dioecious. 

 Calyx rarely foliaceous, generally scarious or membranous, sometimes cup-shaped, 

 sometimes spread into a crown, entire toothed or laciniate ; sometimes divided into 

 palese, or teeth or scales or awns ; sometimes reduced to capillary hairs or bjistles, 

 which are smooth or scabrid or ciliate or plumose, and forming a tuft, either sessile 

 or stipitate ; finally, sometimes reduced to a thin circular cushion, or even entirely 

 wanting. Corolla epigynous, monopetalous, sometimes regular, tubular, 5-4-fid 

 or -toothed, sestivation valvate ; sometimes irregular, either bilabiate or ligulate, 

 each lobe furnished with two marginal nerves confluent in the tube. Stamens 

 5-4, inserted on the. corolla, and alternate with its divisions ; filamiem,ts inserted at 

 the base of the tube, free above, rarely monadelphous, articulated towards the top ; 

 anthers 2-eelled, introrse, cohering into a tube which sheaths the style, very rarely 

 free, usually prolonged into a terminal appendage, cells often terminating in a tail at 

 the base. Ovart inferiorj 1-celled, 1-ovuled, crowned with an annular disk which 

 surrounds a concave nectary; style filiform, undivided in the $ fiowers, bifid in 

 the ? and g flowers ; branches of the style, commonly called stigmas, convex on the 

 dorsal surface, flat on the inner, furnished toward their tops, or outside, with short 

 stiff hairs {collecting hairs), and traversed on tk'e inner edges by two narrow glan- 

 dular {stigmatic) bands, constituting the true stigma ; style much shorter than the 

 stamens before the opening of the flower, but rapidly growing at the period of fer- 

 tilization, traversing the hollow cylinder formed by the anthers, and gathering, by 

 means of the collecting hairs, the pollen destined to fertilize the newly opened neigh- 

 bouring flowers. 5 flowers furnished with stigmatic glands and collecting hairs ; 

 the ? have stigmatic glands but no collecting hairs ; the ^ have collecting hairs 

 and no stigmatic glands; ovule straight, anatropous. Achene articulated on to 

 the common receptacle, generally sessile, provided with a basilar or lateral areola, 

 indicating its point of insertion, often prolonged in a beak to the top. Seed erect. 

 Embryo straight, exalbuminous ; cotyledons plano-convex, very rarely convolute 

 {Bohinsonia) ; radicle inferior. 



K K 



