408 THE COMPOSITE FAMILY. 



its summit as a short border, or more frequently as a pappus : 

 that is, a ring of long, simple or feathery (plumose) hairs, or of 

 small chaffy scales. Corollas either all tubular, with a 5-toothed 

 (or rarely 4-toothed) border, or all ligulate : that is to say, flat, 

 linear or oblong, forming only a short tube at the base ; or else 

 both kinds are in the same head, the central ones tubular, form- 

 ing the disk ; the outer ones ligulate, constituting the ray. In 

 the latter case the head of flowers is said to be radiate, and in 

 contradistinction a head of flowers that has no ray is said to be 

 discoid, and one which has no disk is said to be ligulate. Stamens 

 5 or rarely 4, inserted in the tube of the corolla ; the anthers 

 linear and united (or in Burweed closely connivent) in a sheath 

 round the style. Ovary inferior, with a single erect ovule, and 

 a filiform style divided at the top into 2 short branches bearing 

 the stigmas. Fruit a small, dry, seed-like nut, usually called an 

 achene, crowned by the pappus or sometimes naked. 



The most extensive family among flowering plants, and represented 

 in every quarter of the globe and in every description of station. It is 

 also most easily recognized. The ligular florets are unknown in any 

 other family, and when the florets are all tubular, the Composites are 

 distinguished from the Teasel family, and the few others which have 

 similar heads or florets, by the union of the anthers. In Jasione in- 

 deed the anthers are slightly united, but there, besides other characters, 

 the ovary and capsule have 2 cells with several seeds. The genera are 

 very numerous, and the characters are often taken from differences in 

 the achenes and in the pappus which crowns them, which cannot well 

 be observed until the fruit is ripe. It is therefore particularly neces- 

 sary, in Composites, in collecting specimens for determination, to select 

 such as have the most advanced flower-heads, and these will always 

 be found in the centre of the corymb. 



•-Florets all ligulate (Ligulates) 37 



i Florets all tubular 2 



| Florets tubular in the disk or centre of each head, the outer ones either 

 L ligulate and forming a ray, or slender and filiform (Corymbifers) . 5 

 r Involucre or leaves prickly. Style slightly bulbous under the branches 



2<j (Thistleheads) 29 



I Involucre and leaves not prickly 3 



o f Florets purple, blue, or white 4 



I Florets yellow or greenish, usually small (Corymbifers) .... 5 



. J" Leaves opposite 1. Eupatory. 



I Leaves alternate or radical (Thistleheads) 29 



