COMPOSITE. COMPOUND FLOWERS. 319 



branched, bearing several large handsome heads of 

 lilac flowers, of which the inner are regularly cleft, the 

 outer larger, and generally, though not always, radiate. 

 It is sometimes called Scabiosa arvensis. Fl. July, 

 August. Perennial. 



ORD.' XLYL COMPOSITE. COMPOUND FLOWERS. 



This extensive and well-marked Order derives its 

 name from having its flowers compounded, as it were, 

 of numerous smaller ones called florets, which are in- 

 closed within a calyx-like assemblage of bracts, termed 

 an involucre. These bracts, usually called scales, often 

 overlap one another like the tiles of a house (imbrex) ; 

 hence they are said to be imbricated. The flowers vary 

 greatly in shape, but the following description will be 

 found to include all the British species. Calyx rising 

 from the top of the ovary, and becoming a pappus, that 

 is, either a chaffy margin of the fruit, or a tuft or ring 

 of bristles, hairs, or feathery down ; corolla of one petal, 

 either tubular, or strap-shaped ; stamens 5, united by 

 their anthers (syngenesious) ; ovary inferior, 1 to each 

 style, 1 -celled ; style simple, with a simple or 2-cleft 

 stigma, sheathed by the tube of anthers ; fruit a solitary 

 erect seed, crowned by the pappus, which is sometimes 

 merely a chaffy margin, but more frequently an assem- 

 blage of simple, or serrated or feathery hairs, sometimes 

 elevated on a stalk. For convenience of reference, this 

 Order is divided into several Groups : I. CICHORACEJE 

 (Chicory group}. In this, all the florets are strap- 

 shaped and perfect ; that is, each contains 5 stamens 

 and a pistil. The prevailing colour of British species 

 is yellow, as the Dandelion ; but Salsafy (Tragopogon 

 porrifolius) and Alpine Sow-Thistle (Sonchus alpinus) 

 have purple flowers ; Chicory, blue. In II. CYNAROC- 

 PHAL.E (Thistle Group] the florets form a convex head, 

 and are all tubular and perfect, except in Centaur ea, 



