MORPHOLOGY OF EEPEODQCTIVE ORGANS 159 



Several varieties of regular and irregular polypetalous corollas 

 occur. 



A. Begular Polypetalous Corollas. — Of these there are three 

 characteristic forms, viz. the cruciform or cruciate; the caryo- 

 phyllaceous ; and the rosaceous. 



1. Cruciform or Cruciatc.-'-'Vhis corolla gives the name to 

 the natural order CrucifercB ; but it also occurs elsewhere. It 

 consists of four petals, usually with claws, as in the Wallflower 

 and Stock ; but sometimes without claws, as in the Celandine, 

 and the whole arranged in the form of a cross. 



2. CaryopliyllaceoiM. — This consists of five petals, with long 

 cla^Ys enclosed in the tube of the calyx, and with their limbs 

 commonly placed at right angles to the claws, as in the Cam- 

 pion, Single Pink {figs. 300 and 301), and Carnation. 



3. Rosaceous. — This is composed of five petals, which are 

 sessile or have very short olaiws. They are concave above, and 

 spread regularly outwards, as in the Strawberry (fig. 267) and 

 Single Rose {fig. 302). 



FlC4. 303. FiGf. 304. 



Fig. 302. Flower of the Bose. h. Bract, ct. Tube of the 

 calyx, cf, cf, cf. cf. cf. Divisions of tlie calyx, p. p, p. 



p.p. Petals. Fiij. 303. The flower of tlie Sweet Pea 



(Lathyms odorati/s). c. Calyx, if. Vexillum. a. Ala: or 



wings, car. Carina or keel. Fig. 304. Plower of 



Spigelia marylandica. c. Calj x. /. Tubular corolla. I. 

 Limb of the corolla, s. Summit of the style and stigmas. 



B. Irregular Polypetalous Corollas. — There are many ano- 

 malous forms of irregular polypetalous corollas to which no 

 particular names are applied. There is one, however, namely 

 the Papilionaceous, which is of considerable importance, as it 

 occurs in all British Leguminosce. This derives its name from 

 the fancied resemblance which it bears to a, butterfly. It is 

 composed of five petals {figs. 303 and 464), one of which is 



