172 Mr. D. Don's Desct'iptions of ntw Genera and Species 



Pistillum: orormm inferum, indehiscens: disco epigy no: ovulo 



erecto, solitario, funiculis 2 pistillaribus manifestis suspense: 



stylus e duobus conflatus, indivisus : stigmata 2, saepiiis so- 



luta, patentia. 

 Fructus (Achenium) : pericarpium indehiscens, monosper- 



mum. 

 Semen: testa duplex; exterior coriacea v. Crustacea; interior 



membranacea, vascularis, vasis propriis et spiralibus in- 



structa : albumen nullum. 

 Embryo dicotyledoneus, erectus, seminis cavitati conformis : 



cotyledones oblongne : radicula his persape brevior, obtusa, 



centripeta. 

 Plantae polymorphae in orbis temperatis vulgatissimae. 



The Composites constitute the most extensive and the most 

 interesting portion of the vegetable kingdom ; and their distri- 

 bution is so universal, that they form a large proportion of the 

 Flora of almost every country : but countries traversed by ex- 

 tensive mountain-chains, and situate within or near the tropics, 

 are found to be most favourable to the development of the 

 plants of this class : for in the Floras of Peru, Chile, and 

 Mexico, they appear to constitute a sixth part of the whole 

 phsenogamous vegetation ; and this estimate of their number is 

 justified by an actual comparison both of the published and un- 

 published plants of these countries. 



The CompositcB are related on the one hand to Calycerea, Dip- 

 saceay and Valerianea ; and on the other to Campanulacea. and 

 GoodenovicB ; but the disposition of the primary vessels in the 

 corolla essentially distinguish them from every other family. 

 The plurality of styles, the inferior monospermous ovarium, 

 and the presence of an epigynous disk, show at least a con- 

 siderable degree of analogy, if not of affinity, to the Umbelliferce, 



to 



