COMPOSITE FAMILY 247 



the progress made by Botany during the last hundred years, since 

 the total number of species known to Linnaeus was only 8,500. 

 The Composites form a very natural Order, all agreeing in a 

 large number of characters, especially in the capitate inflorescence, 

 or crowding together of the florets, or little flowers, into a head, 

 or " compound flower," as Linnaeus called it, to which the Order 

 owes its name, and in the union of the anthers referred to in the 

 name of the co-extensive class Syngenesia in the Linnaean system. 

 Though they manifest their success in the struggle for existence 

 not only by their great number of genera and species, but also by 

 a striking profusion of individuals, as is familiar to us all in the 

 cases of Thistles, Daisies, Dandelions, &c, and by a world-wide 

 geographical distribution, they seldom reach the dimensions of 

 shrubs, few of them being even woody. They must be con- 

 sidered, however, as on the whole the most highly organised 

 members of the Vegetable Kingdom. Their leaves are exstipulate, 

 generally simple, and mostly scattered. The heads are generally 

 many-flowered, and are surrounded by one or more whorls of 

 scales or bracts forming an involucre, which is often imbricated, 

 the scales overlapping like the tiles of a house (Latin imbrex, a 

 tile). The common receptacle, on which the florets are situated, 

 varies in shape, being flat, concave, or convex, and in surface, 

 being sometimes smooth and naked, and in other cases pitted or 

 furnished with scales or bristles, known as pales. The florets, 

 which are true flowers, though generally small, may be all alike 

 in form or colour or both, as in Thistles, Dandelions, Groundsel, 

 &c, or the outer or ray-florets may differ from the inner or disk- 

 florets in form, as in the Corn-Marigold, or in colour also, as in 

 the Daisy. The calyx is superior, and there are 5 sepals, though 

 they are seldom distinguishable, the limb, if present, being 

 generally represented by a pappus of hairs, which may be sessile 

 on the fruit, as in the Thistle, or stalked, as in the Dandelion, 

 when the fruit is termed beaked, the hairs themselves being 

 feathery or plumose, as in the former, or simple or pilose, as in 

 the latter. The corolla consists of 5 valvate petals, either tubular 

 and polysymmetric, as in all the florets of Thistles and Groundsel 

 and the disk-florets of the Daisy, or tubular below and ligulate or 

 strap-shaped above, as in all the florets of the Dandelion and the 

 ray-florets of the Daisy. The florets may be all perfect, as in 

 Thistles and Dandelions ; or the ray-florets may have no stamens, 

 as in the Daisy, or be neuter, having neither stamens nor ovary, 

 as in the Cornflower ; whilst the disk- florets may be perfect, as in 

 the Daisy, or exclusively staminate, as in the Garden Marigold. 

 Occasionally all the florets may be staminate or all carpellate, and 



