THE COROLLA 



215 



307. The Ligulate, or strap-shaped corolla, seen in the 

 rays of the sunflower family, is of such frequent occurrence 

 as to deserve a special examination. If 

 you will remove one of the small blos- 

 soms from the disk of any large composite 

 flower (Fig. 426) 

 and imagine its 

 corolla greatly en- 

 larged and split 

 open on the inner 

 side, you will get 



a very good idea of 426. — a head of artichoke 427. — A ray flower of 

 the nature of the ^°'"'^'^ divided lengthwise. artichoke, enlarged. 



rays. The five little teeth into which it is usually cleft 



at the top show the number of lobes or petals of which 



it is composed. The corolla of the lobelia 



St. /ss^ .-.ss^-^^ represents an intermediate state between 



the tubular and ligu- 

 late forms (Fig. 4i29). 



308. Bilabiate Co- 

 rollas. — By far the 

 most important and 

 widely distributed of 

 sympetalous corollas 

 is the bilabiate, or 

 two-lipped kind, dis- 



429, — Fio'wer oiLo^eHa 

 cardinalis, with tube of tinctivC of the mint 



. — A vertical 

 section of a disk flower, 



showing the divided corolla divided on one 



style, st, and the sta- side; filaments and an- 



mens, J, s, with their thers united into a tube and their allied 



anthers united (syn- {after Gray) : f, tube of 



genesious) , filaments ; a, anthers. 



and figwort families 



known species. 



groups, numbering in 

 all over six thousand 

 They are of many varieties, from the 

 scarcely perceptible irregularity of the verbena and mullein 

 to the complicated structures of the sage, snapdragon, and 

 toad flax. Two of them are so strongly marked that 

 they have received special names. These are the ringent, 

 or open-mouthed, and the personate, or closed (Figs. 430 



