232 | POLYPETALOUS COROLLAS. 
will be described hereafter (page 237). In texture the petals 
are commonly soft and delicate, but they sometimes differ widely 
from this, and become thick and fleshy, as in the Stupelias ; or 
dry and membranous, as in the Heaths; or stiff and hard, as 
in Xylopia. 
In describing their direction, we use the terms erect, connivent, 
divergent, patulous, or refleved, in the same sense as already 
described when speaking of similar conditions of the sepals (page 
225). 
The petals also, like the sepals, may be either distinct or 
more or less united into one body. In the former case, the 
corolla is said to be polypetalous or dialypetalous (figs. 474-477) ; 
in the latter monopetalous or gamopetalous (figs. 478-495). The 
same objection applies to the use of the term monopetalous 
as to that of monosepalous already mentioned (page 225), but 
we shall continue to employ it from its being the one more 
commonly in use. 
1. POLYPETALOUS OR DIALYPETALOUS CoroLLA.—The number 
of petals which enter into the composition of the corolla is indi- 
Fic. 476. 
Fie. 477. 
Fig. 476. Flower of the Rose. 6. Bract. et. Tube of the calyx. cf, cf, cf, cf, 
cf. Divisions of the calyx. p, p, p, p, p. Petals.——Fig..477. The flower 
of the Sweet Pea (Lathyrus odoratus). c. Calyx. v. Vexillum, a, Ale or 
wings. ca7. Carina or keel. 
cated, as in the case of the polysepalous calyx, by the prefix of 
the Greek numerals. Thus a corolla of two petals is said to be 
dipetalous ; of three, tripetalous ; of four, tetrapetalous; of five, 
pentapetalous ; of six, hexapetalous ; of seven, heptapetalous ; of 
eight, octapetalous ; and so on, 
When the petals are all of the same size, and of like figure 
or form, and arranged in a symmetrical manner, the corolla is 
termed regular, as in Rosaceous flowers (jigs. 456 and 476); but 
when the petals vary in these particulars, as in the Pea and allied 
plants (figs. 452 and 477), it is said to be irregular. Some varieties 
of polypetalous corollas have received special names which we 
