82 SOUTH AFRICAN BOTANY 
attractive functions as the corolla, being similar in size 
and colour. The calyx is then said to be PETAuoID. 
In many members of the Compositae (e.g. Thistle, Corn- 
flower) the calyx has been reduced to a ring of hairs 
called a Pappus, and this helps subsequently in fruit dis- 
persal. In other cases the persistent calyx takes a great 
share in the formation of the fruit, e.g. Apple, Oak. 
50. The Corolla—The corolla is usually much more 
Fie. 47.—Calyces. 
I. Tubular. IT. Obose. III. Urceolate. IV. Saccate. (From 
“Thome’s Botany ”’.) 
conspicuous and much more delicate in structure than 
the calyx. Itmay be GAMOPETALOUS or POLYPETALOUS. 
Its chief function is to attract insects, for which purpose 
it is often highly coloured and sweet scented. It may 
also protect the stamens and carpels. It rarely persists 
after fertilization. 
The following terms are used when describing the 
petals :— 
UNGUICULATE, or clawed, if they are broad above and 
form a narrow limb below. 
