THE FLOWER 909 
Calyx. The calyx, like the corolla, 
may be composed of a number of 
separate units, which in this case are 
called sepals (Fig. 202), or of a some- 
what tubular or funnel-shaped struc- 
ture with lobes which represent the 
sepals. The calyx is typically small 
and green. The function of the calyx 
seems to be to protect the inner parts 
of the flower before the flower bud 
has opened. 
Frequently the perianth consists 
of only one set of structures, and 
in such a case this set is regarded 
as a calyx, the corolla being con- 
sidered as absent. When _ there 
is no corolla, the calyx is often 
bright-colored and conspicuous and 
takes the place of the corolla in > 
its function of attracting insccts. 
In many of the monocotyledonous 
plants the sepals are large, bright- 
colored, and very similar in appearance to the petals (ig. 214). 
Flower stalk. ‘The 
flowers are joined to 
the stem by a central 
axis, or stalk, which 
is usually composed of 
two parts: the stalk 
proper, which is known 
as the pedicel, and an 
expanded terminal por- 
tion, the torus, or recep- 
tacle, on which the other 
parts of the flowers are 
-borne (Fig. 3). Left, female ; right, male. (x 2) 


Fig. 209. Flowers of castor-oil 
plant 
Above, female flowers; below, 
male flowers. (x 1) 

Fig. 210. Flowers of papaya (Carica papaya) 

