Unisexual Flower

Unisexual Flower

 

a flower having stamens but no pistils or having pistils but no stamens. A flower having only stamens is said to be staminate, or male. A flower having only pistils is said to be pistillate, or female. In many unisexual flowers, the nonfunctioning organs of the other sex are present in reduced form, thus attesting to the plant’s original bisexual nature. Such flowers are said to be functionally male or functionally female.

The distribution of unisexual flowers on plants varies.

References in periodicals archive ?
carpellate: Unisexual flower having carpels but no stamens.
Some Ascarina species have the simplest possible unisexual flowers, which consist of one stamen or one carpel containing one ovule, borne in the axils of bracts in spicate inflorescences, although others have stamen numbers ranging from two to five, lateral bracts associated with the stamen and/or carpel, groups of two carpels, or both a stamen and a carpel (Swamy, 1953; Smith, 1976, 1981; Moore, 1977; Jeremie, 1980).
Deceitful pollination by anther-mimicking stigma had been known earlier only in cases of species with unisexual flowers. Therefore, C.
Developmental analyses reveal early arrests of the spore-bearing parts of reproductive organs in unisexual flowers of cucumber (Cucumis sativus L.).
In the Arecaceae family as a whole, the evolution of floral characters has been observed, including progression from bisexual to unisexual flowers, and from monoic to dioic species (Moore and Uhl, 1982; Daher et al., 2010).
americanus, has been described as having dioecious, unisexual flowers with either stamens or gynoecium aborting (Green 1958; Nesom 2012).
Despite this diversity, Robbrecht (1988) pointed out the presence of three reproductive strategies common in Rubiaceae-distyly, morphologically characterized by the presence of two inter-compatible floral morphs, which is generally observed in species of Rubioideae (Barrett, 1992); stylar pollen presentation involving protandry and pollen presentation in the style which is generally recorded in Ixoroideae (De Block and Igerscheim, 2001; Nilsson et al., 1990) and the occurrence of unisexual flowers in certain species almost restricted to Theligoneae and Anthospermae (Robbrecht, 1988).
Scleria and Carex are the only members of the Cyperaceae in our flora with unisexual flowers. These imperfect flowers occur in spikelets that consist of 3-10+ scales, the lower 2-4 scales being empty, the lower fertile scales being pistillate, the upper fertile scales staminate or sometimes empty.
Historically, the designation "male" and "female" parts have often been applied to the stamens and carpels, respectively, and thus with unisexual flowers one might see reference to the male or female flower.
Different flower sexes and breeding systems have been reported for Bromeliaceae (Table 1) ranging from bisexual flowers to unisexual flowers and from xenogamy to cleistogmy.
Organ initiation and the development of unisexual flowers in the tassel and ear of Zea mays.
Dioecious A plant or species having unisexual flowers; staminate and pistillate flowers on separate plants.