STRUCTURE.] IRREGULAR COROLLA. 335 



talous corolla are arranged, they have received different 

 names, which are thus defined by Link : the rosaceous corolla 

 (fig. 97.) has no claw, or it is very small; the liliaceous 

 (fig. 71.) has its claws gradually dilating into a limb, and 

 standing side by side ; a caryophyllaceous has long, narrow, 

 distant claws; the alsinaceous has short distant ones; the 

 cruciate flower has four valvaceous sepals, four petals, and six 

 stamens, of which two are shorter than the rest, and placed 

 singly in front of the lateral sepals, and four longer, and 

 standing in pairs opposite the two other sepals. If the corolla 

 is very irregular, with one petal very large and helmet- shaped, 

 or hooded, as in the calyx of Aconitum, it is sometimes called 

 cassideous ; if it resembles what is called labiate in monope- 

 talous corollas, it is termed labiose. The corolla of the Pea, 

 and most Leguminous plants, has received the fanciful name 

 of papilionaceous or butterfly -shaped } (figs. 98, 99.) ; in this 



98 



there are five petals, of which the upper is erect and more 

 expanded than the rest, and is named the standard or 

 vexillum ; the two lateral are oblong, at right angles with the 

 standard, and parallel with each other, and are called the 

 wings or alee ; and the two lower, shaped like the wings and 

 parallel with them, cohere by their lower margin, and form 

 the keel or carina. The wings were formerly called talarae 

 by Link, and the keel scaphium by the same author. 



When the corolla is very small, or when it forms a part 



