The staminate flower
consists of solid pedicel, and the calyx cup is five toothed.
The Betuloideae share features such as laminar secondary bracts and one to three flowers in the pistillate cyme, tepals in the staminate flower
, tracheids in wood, pollen with arci and nutlets with wings.
are located in shallow alveoli, forming small intumescences that are easily visible to the naked eye; each staminate flower
is composed of two tepals and two stamens (Fig.
The involucral bract and bracteoles of the staminate flower
have a single-layered epidermis on both surfaces (see Figure 2A, B).
(2004) reported that ethrel 100 ppm and [GA.sub.3] 50 ppm, respectively induced the first staminate flower
at the lowest node in bitter gourd; and Arora et al.
By dropping of the petals at the end of the staminate stage, the pollen-covered insects were forced to leave the flower and eventually flew to a scented pistillate or staminate flower
(WEBBER and GOTTSBERGER, 1995).
The individual unisexual flowers lack a perianth, the pistillate flower consisting of 1 (rarely 2) pistil(s) subtended by a scale, and the staminate flower
consisting of 1-3 stamens borne in a scale.
with 3 sepals, these ovate, acuminate, 0.9-1.4 mm long, connate basally in 0.2-0.3 mm, not reaching the total length of corolla tube, petals 3, ovate to rhomboid, fleshy, 4.5-5.5 mm long including an acumen of 0.4-1 mm long, connate basally in 2-3 mm, stamens 6, conspicuously exserted from the petals, alternating 1 antisepalous stamen and 1 antipetalous stamen, filament tapered, 1.5-2 mm long, basally inflated and 0.4-1 mm thick, connected to anther at proximal 1/4-1/3 of its length, anthers 4.5-6.5 mm long, thecae separated in the proximal 1/4 of their length, connective not projected, pistillode trifid, 0.7 mm long.
with 3 sepals 0,5-0,7 mm long; petals 3, 2,5-3 mm long, connate in the proximal part; stamens 6, anthers 1-1,2 mm long, filaments 1,5 mm long; pistillode minute, 3-parted.
more flower buds aborted during development), significantly fewer pollen grains per staminate flower
, and marginally smaller pollen grains than undamaged branches on the same plants.
Inflorescences with 2 sterile basal articulations and 2(-3) floriferous segments, each flower area with one terminal staminate flower
and two lateral pistilate flowers.