BULLETIN 61, HAWAII EXPERIMENT STATION 
simple characters as arrangement of inflorescence and form of fruit 
by means of which the types may the more easily be identified. In 
Hawaii the types are commonly designated as dioecious or round- 
fruited (fig. 1) and monoecious or long-fruited. (Figs. 2 and 3.) 
The Solo papaya (fig. 4) is in reality a strain of the dioecious type. 
None of the three kinds are correctly designated by the above-men- 
tioned terms inas- 
much as they exhibit 
numerous variations 
of sex forms in the 
flowers and differ- 
ences in size and 
shape of fruit. This 
subject is discussed 
more in detail under 
Variations, p. 10. 
The papaya is a 
large herbaceous 
plant which at ma- 
turity may attain a 
height of 25 or 30 
feet. It is sometimes 
called a tree and is 
also likened to a 
palm, but it is not 
botanically related to 
the palms. In struc- 
ture the papaya is 
dicotyledonous, the 
trunk is hollow, and 
the wood fleshy. 
Normally the trunk 
is erect and while 
young usually con- 
sists of a single 
shaft. (Fig. 5.) 
After two or three 
years of growth it 
may develop upright 
branches, each of 
which tapers to a 
terminal containing 
a cluster of leaves. 
(Fig. 6.) The bark 
is smooth and gray- 
ish, and is marked 
by prominent leaf scars. When cut or scratched, the outer surface 
freely yields a thin milky juice. Ordinarily the plants are short- 
lived, and after three or four years the growth slows down, and the 
leaves and fruit diminish in size. At this stage, the plants soon die 
or are removed by the grower to give place to more profitable 
crops. Papaya plants when grown under very favorable conditions, 
Figure 2. — Monoecious type of long-fruited papaya, 
form of fruit is well adapted for marketing 
This 
