156 The Composites. 



We have finished our examination of a flower taken from towards the 

 centre of the capitulum. But around the edge are very different flowers. 

 They are called ray-fiorets : those within are disk-florets. In some genera, 

 the ray-florets differ from those of the disk in one point only, — the corol is 

 longer, and opened out into a strap, looking like a single petal. Other genera 

 have the ray-florets pistillate, as the asters and elecampane. But in the sun- 

 flower the rays are a perfect sham : their only office, like that of some mem- 

 bers of modern society, is to look well. A showy corol stands as an abor- 

 tion of an achenium ; and that is all : such florets are called neutral. Others 

 again, as the compass-plant and pot-marigold, have the florets diclinous, 

 the rays pistillate, and the disk staminate. Other genera, again, have dicli- 

 nous capitula ; as the ambrosia, ragweed, hogweed, bitterweed, or Roman 

 wormwood. Here the pistillate capitulum has but one floret, and this de- 

 velops into a sort of nut. The miserable cockle-burr, or clot-burr (Zanthium), 

 is of this kind too. Its fertile capitulum is two-flowered, and ripens into 

 a two-seeded nut, with hooked prickles, that take tenacious hold of stock- 

 ings, or any fibrous substance that touches them. 



Many compositae have no ray-florets, and are called discoid ; while those 

 which have are called radiate. Among the radiates, the thistles, burdock, 

 and blue-bottle or bachelor's-button, are well known. The last has the 

 outer florets larger and neutral ; but they are tubular. The composites that 

 have tubular florets form the first and by far the largest sub-order, the Tu- 

 biflorce. The third, the Liguliflorce, has all the corols strap-shaped ; as the 

 dandelion, cichory, and salsify. The second sub-order is unknown in the 

 Northern States ; but a single species is found at the South, — Chaptolia 

 tomentosa. The sub-order is called Labiatiflorcz^ and has the corols of the 

 perfect florets cleft into two lips. None of them are found in Europe or 

 Northern Asia. Most are South-American, and some of them very beau- 

 tiful ; the mutisias, for instance. 



In 1846, Lindley estimated the genera of compositae at a thousand and 

 five, and guessed the species at nine thousand. The eight hundred and 

 thirty-seven genera described by Endlicher a few years earlier were divided 

 as follows : Tubiflorae, seven hundred and three ; Labiatiflorae, sixty-six ; 

 Liguliflorae, sixty-eight. But the two-lipped genera are much poorer in 

 species than the others. 



