Botany and Improvement 23
ten, with different degrees of fusion. This type of flower produces irregu-
larly shaped fruit known as carpelodic (cat face), with little commercial
value. These flowers appear more frequently when ambient temperatures
are 24.5°C during the day and 15.5°C at night.- Hermaphrodite elongated flower: Petals of this type of flower are fused from
one-fourth to three-fourths of their total length; ten anthers are observed,
five long and five short. The ovary is long and when it contains five or more
carpels, the form of the fruit varies from cylindrical to pear-shape (De Los
Santos et al. 2000). Among different types of hermaphrodite flowers, this is
the most commercially important. - Hermaphrodite sterile flower: It is a flower that resembles the former, but
does not develop an ovary and hence it is sterile due to warm temperatures
or water stress. It produces pollen only and considered a functional male
flower (De Los Santos et al. 2000). - Typical male flower: This type of flower has a long and thin corolla contain-
ing anthers in two series of five, one series longer than the other. They have
a rudimentary pistil no stigma and are non-functional (De Los Santos et al.
2000). According to aforementioned flower types, plants are also catego-
rised into four groups:
a. Group I – Pistillate or female plant producing Type A flowers.
b. Group II – Hermaphrodite or bisexual plant may bear flowers of Type
B, C and D. Mostly, it has Type B in summer, Type D in winter, Type C
during transition periods and rarely Type E.
c. Group III – Summer sterile hermaphrodite plant produces Type E in winter
and pseudo Type D in summer (sometimes, it is considered as aberrant of
Group II).
d. Group IV – Staminate or male plant producing Type F flowers which
are usually born but occasionally Type E flowers appear.
Storey (1958) classified papaya plants in 31 heritable phenotypes on the basis of
peduncle length, ramification and seasonal sexual responses. Fifteen of these are
variations among staminate plants and 15 are variations among hermaphrodite or
andromonoecious plants. The remaining phenotype is the pistillate plant. Later, these
phenotypic variations were broadly grouped into eight distinct types, namely (1) sta-
minate, (2) teratological staminate, (3) reduced elongata, (4) elongata, (5) carpelloid
elongata, (6) pentandria, (7), carpelloid and pentandria and (8) pistillate. This group-
ing greatly simplified numerous overlapping and removed confusions with respect to
sex types. Fisher (1980) has reported that the perfect flower of the hermaphrodite, the
pistillate flower of the female and the staminate flowers of the male are regarded as
normal types. All polymorphic forms are regarded as teratological (i.e. abnormally
modified), representing residual phylogenetic transitional stages between the perfect
flower and the pistillate flower on the one hand, and the perfect flower and the stami-
nate flower on the other hand (Ray 2002).
A hermaphrodite plant normally produces reduced elongata, elongata, carpelloid
elongata, pentandria and carpelloid- and pentandria-type flowers (Figure 2.4). A
male plant produces staminate flowers, while a female bears only pistillate flowers.