168 THE CLASSES SYNGENESIA AND GYNANDRIA. 



when cultivated may be eaten with impunity ; Prenanthes, or Wall-lettuce ; Leontodon 

 taraxacum or Dandelion, with milky medicinal juices ; Sonchus or Sow Thistle ; Hiera- 



Fig. 357. Fig. 358. 



Detached floret of the ray in the Polygamia Superflua. Polygamia Equalis. 



cium or Hawk Weed ; Apargia or Hawkhit ; and Tragopogon or Goat's Beard. The ten 

 remaining genera have all the corollas tubular ; six with the florets spreading so as to 

 form a hemispherical head and face, with the florets lying parallel and crowded together, 

 and forming nearly a level surface at the top. Amongst the former are the Carduus and 

 Cnicus, two forms of prickly thistle, and Arctium or Burdock ; and of the latter are the 

 Bidens or Bur Marigold, Diotis, Eupatorium, and Chrysocoma. 



The second order is Polygamia Superflua, in which all the florets are fertile ; but 

 yet in many cases those of the ray have pistils only. The marginal florets appear 

 wanting in the Artemesia or "Wormwood, Tanacetum or Tansy, Gnaphalium or Cud- 

 weed, and Conyza or Spikenard ; whilst they are developed, and have a strap-shaped 

 figure, in all the remaining orders. Amongst the latter are found the modest " wee 

 crimson tipped flower," the Bellis Perrennis, Tussilago farfara or Colt's-foot, Anthemis 

 or Camomile, Achillea or Millefoil, Senecio or Groundsel, Aster or Starwort, Chrysan- 

 themum or Ox-eye, and Corn Marigold, Pyrethrum or Fever-few, Solidago or Golden 

 Rod, Inula or Fleabane, and Cineraria or Fleawort. 



The third order is called Polygamia Frustranea, and has perfect and fertile florets of 

 the disk ; but the florets of the ray have neither stamens nor pistils, and hence the 

 term " Frustranea." The Centaurea, or Centaury, is the only genus, with its seven 

 species. 



On taking a review of this extensive class we find that the Lettuce, in its cultivated 

 state, and the dried root of the Chichorium, are the only members which afford nutri- 

 ment to man. Certain others, as the Sonchus, Leontodon, Carduus, Cnicus, and 

 Senecio are eaten by various animals. Many members have been more or less 

 employed medicinally, and it is probable that medicinal properties are possessed by the 

 whole class. Those which have been most commonly used are the Anthemis, Tus- 

 silago, Artemesia, Leontodon, Hieracium, and Inula. Some of these, with the 

 Lactuca and many other members of the class, abound in Laticiferous tissue and milky 

 juices ; and to these may chiefly be attributed the medicinal effects of the plants. They 

 grow exclusively, or nearly so, on dry land, and many of them in waste places. But 

 few have been thought worthy of horticultural cultivation. 



CLASS XX. GYXANDKIA. 



This is a very curious class of plants, and at the present day are very fashionable. 

 In this country they grow chiefly in meadow lands and moist soils ; but in tropical 



