192 COMPOSITE. 



28. COMPOSITE. 



Calyx superior, quite adherent to the ovarium, from 

 which it is inseparable ; its limb modified so as to form 

 scales, or pappus, and very seldom abortive. Corolla 

 monopetalous,ligulate or tubular ; when tubular five cleft, 

 and valvate in aestivation. Stamens 5, placed on the 

 tube of the corolla, and alternate with its divisions, fila- 

 ments free, (rarely as in the Ambrosise monadelphous). 

 Anthers narrow, two-celled, united together so as to 

 form a tube, (Syngenesious) rarely as in Xanthium dis- 

 crete. Ovarium inferior, one-celled, with a single erect 

 ovule ; style simple ; stigmas two, distinct or united. 

 Fruit small, dry, and indehiscent (Achenium), crowned 

 with the limb of the calyx. Seed solitary and erect, 

 exalbuminous ; embryo taper and erect, and the radicle 

 inferior. 



Herbs or shrubs with exstipulate, alternate or opposite 

 leaves. Flowers collected upon a general receptacle, 

 each one of the collection being termed a floret, the 

 whole surrounded by a common involucrum. Bracteoe 

 when present forming the chaff of the receptacle. 



Geographical Relations. They predominate in relative 

 proportions to other flowering plants within and near the 

 tropics, and their ratio is lowest within the arctic circle ; 

 but some divisions of the tribe are most abundant in the 

 cold countries, and others only in the hot ones, as will 

 presently be seen. 



This family is divided into sub-tribes ; the following 

 are Officinal: 



Corymbiferce. 



Composite having tubular florets in the disk, and ligu* 

 late ones in the ray of the collection, and a non-tumid 

 style. 



