CLASSIFICATION OF ANGIOSPERMS. 711 



eral character, except that the flowers are of a bright dark blue 

 color or occasionally white. 



c. FAMILY COMPOSITE.— This is a large group of plants, 

 which are annual, biennial, or perennial herbs, under-shrubs, 

 shrubs, trees and twiners or even climbers, a few being aquatic. 

 They contain inulin, a constituent peculiar to this group of plants. 

 The most distinguishing character is the inflorescence, which is 

 a head or capitulum (Fig. 228), consisting of one or two kinds 

 of flowers, arranged on a common torus, and subtended by a 

 number of bracts, forming an involucre. The flowers are epigy- 

 nous and the fruit is an achene, usually surmounted by the per- 

 sistent calyx, which consists of hairs, bristles, teeth or scales, 

 which are known collectively as the pappus (Fig. 227). 



The individual flowers are called florets (Figs. 241, 242), and 

 may be hermaphrodite or pistillate, monoecious, dioecious, or 

 neutral. Depending upon the shape of the corolla, two kinds of 

 flowers are recognized, one in which the corolla forms a tube, 

 which is 5-lobed or 5-cleft, known as tubular flowers (Figs. 

 22y, 22S, C) ; and one in which the petals are united into a short 

 tube, with an upper part that forms a large, strap-shaped, usually 

 5-toothed limb, known as ligulate flowers (Figs. 227, 228, D). 



In some of the plants of the Compositae the head consists of 

 ligulate flowers only, but in the larger number of plants the head 

 is composed of both tubular and ligulate flowers or tubular flowers 

 alone and accordingly two main groups or sub-families are dis- 

 tinguished. The sub- family in which all of the flowers are lig- 

 ulate is known as Liguliflor.e, or Cichorl\ce.e, by those who 

 give the group the rank of a family. This group includes plants 

 like dandelion, chicory, lettuce, and Ilieracium. The group or 

 sub-family in which the flowers are all tubular or ligulate on the 

 margin only is known as the Tubuliflor/E. When the head 

 consists only of tubular flowers it is called discoid, but when 

 ligulate flowers are also present it is called radiate. \Mien the 

 heads are radiate, as in the common daisy, the tubular flowers 

 are spoken of as disk-flowers, and the ligulate flowers as ray- 

 flowers. The disk-flowers are usually perfect, while the ray- 

 flowers are pistillate or neutral (without either stamens or pistils). 

 By some systematists the Tubuliflorse are divided into groups 



