Botany and Improvement 15
Female flowers are much larger than male flowers, around 4.0–5.0 cm long, and
are more or less sessile on the main axis. They have a short calyx-tube with five short
lobes, and five waxy, yellow petals united at the base but free for most of their length
and with twisted, pointed tips. The large superior ovary is sessile, globular and green
with five much branched sessile stigmas. It is composed of five united carpels with
a single locule which contains many ovules on parietal placenta. They are produced
in cymes 2.5–10.0 cm long, bearing one to six flowers. All the female flowers are
purely pistillate without any visible evidence of stamen vestiges. This form of tree
does not respond to the physiological influences that cause sex reversals in certain
hermaphrodite and male trees.
The hermaphrodite tree has cymes which are 2.5–25.0 cm long, bearing one to
six flowers. Usually, the terminal flowers of the primary and secondary peduncles
are perfect. Flowers from tertiary and lower orders of peduncles may be perfect or
staminate. Most hermaphrodite plants are subject to ‘sex reversal’ or modification.
The change of sex occurs, from male to female, but never from female to male.
The hermaphrodite flower in case of ‘elongata’ has elongate ovary which devel-
ops into a more or less cylindrical, pyriform or oblong fruit depending on cultivar
or strain. This is commonly referred to as the perfect flower. Its calyx is typical of
the calyxes of all papaya flowers. The corolla is large, more or less fleshy, and sym-
petalous for one half to three fourth of its length. It has 10 versatile introse stamens.
These are coalesced into a monadelphous ring found at throat of the corolla tube.
Typically, the pistil is five-carpellate and uniloculated, with parietal placentation. In
some flowers, however, the number of carpels may lie between one and ten. The fruit
develops from a superior ovary.
A reduced type of hermaphrodite flower is frequently seen in sex reverting her-
maphrodite and male trees. It has a very short androperianth tube which is adnate to
the base of the pistil, with five stamens on relatively long filaments. The lobes of the
five carpellate pistils occupy positions which in the elongata flowers are occupied by
stamens of the upper set. Superficially, the lobes of the carpels appear to lie oppo-
site the corolla lobes rather than alternate as in the elongata flower. They are called
pentandria because they contain only five stamens.
2.2.1 Description
A Staminate
♂
: Bracteolate, sessible in cluster or raceme, incomplete, actinomorphic,
bracts-leafy or scaley, hypogynous, funnel shaped 2.5–3.2 cm long
Calyx : Sepals 5, gamosepalous, small, light green, lobed 5
Corolla : Petals 5, gamopetalous, tube-like, elongated, yellow-coloured
Androecium : Stamens 10, in two whorls, interones are smaller, epipetalous
(joined with petals), anthers-bilocular, introse
Gynoecium : Absent
Fruit : Absent
Seeds : Absent
Floral formula : ♂ K (5) A5 + 5G0(Continued )