MONOPETALOUS COROLLAS. 



181 



or completely covered by the alae, and often united slightly by their 

 lower margins, so as to form a single keel-like piece, b, called carina, 

 or keel, which embraces the essential organs. This 

 corolla occurs in the Leguminous plants of Bri- 

 tain, or those plants which have flowers like the 

 pea. Among the irregular polypetalous corollas 

 might be included the orchidaceous, although it is, 

 properly speaking, the perianth of an Endogen. 

 This perianth consists of three outer portions 

 equivalent to the calyx, and three inner alternat- 

 ing with them, constituting the petals. The latter 

 are often very irregular, some being spurred, 

 others hooded, &c. ; and there is always one, called the labellum or lip, 

 which presents a remarkable development, and gives rise to many of 

 the anomalous forms exhibited by these flowers. 



380. Regular Moiiopetiilous or Gamopetalons Corollas. These are 



sometimes campanulate or bell-shaped, as hi Campanula rotundifolia (fig. 

 293); infundibuliform or funnel-shaped, when the tube is like an inverted 

 cone, and the limb becomes more expanded at the apex, as in Tobacco 

 (fig. 294 ;) hypocrateriform or salver-shaped, when there is a straight 

 tube surmounted by a flat spreading limb, as in Primula (fig. 295) ; 



293 294 295 296 



tubular, having a long cylindrical tube, appearing continuous with the 

 limb, as in Spigelia (fig. 287), and Comfrey (fig. 296); rotate or wheel- 

 Fig. 292. Irregular polypetalous corolla in the papilionaceous flower of Lathyrus odoratns, or 

 Sweet-pea, c, Calyx, e, Vexillum or standard, a, Two alae or wings, b, Carina or keel, formed 

 of two petals. 



Fig. 293. Regular monopetalous or gamopetalous campanulate or bell-shaped corolla of Cam- 

 panula rotundifolia. c, Calyx. I, Limb of corolla, s, Stigma. 



Fig. 294. Regular monopetalous or gamopetalous infundibuliform corolla of Nicotiana Taba- 

 cum, or Tobacco. The letters as in tig. 293. 



Fig. 295. Regular monopetalous or gamopetalous hypocrateriform corolla of Primula elatior, 

 or Oxlip. c, Calyx, p, Corolla, t, Tube. I, Limb, a, Anthers. 



Fig. 296. Regular gamopetalous tubular corolla of Symphytum officinale, or common Comfrey. 

 c, Calyx, t, Tube of corolla. I, Limb. *, Stigma, r. External depressed surface of folds which 

 project into the tube of the corolla. 



