Sexual phenotype of Capparis herbacea (Capparaceae)

Authors: NANA SHAKARISHVILI, LIANA OSISHVILI

Abstract: Floral morphology coupled with the morphometry of androecium revealed that Capparis herbacea Willd. has an andromonoecious sexual system, producing both male and perfect flowers on the same plant. Functionally male flowers develop more stamens with larger anthers than bisexual ones (63.6 ± 0.6 and 4.1 ± 0.01 mm; 58.1 ± 0.7 and 3.6 ± 0.02 mm, respectively). The ratio of male to perfect flowers ranges from 0.5 to 2.6 during the flowering season. The development of dense trichomes on the adaxial surface of the cavity made by variegated connate petals is presumably adaptive and serves to protect nectary exudate from evaporation in a hot and dry environment. Air temperatures below 30 °C and successful cross pollination-rather than light and relative humidity-limit florescence time and duration. No preference for flower morphs was observed during pollinator visitations. These data confirm the pollen donation hypothesis regarding the role of male flowers in andromonoecious plants. It is a primary benefit of effective pollination in Capparis herbacea, a species with a short blooming period. Results also indicate that Capparis herbacea is the second member of the section Capparis L., after Capparis spinosa L., in which the coexistence of male and hermaphrodite flowers on the same plant has been reported.

Keywords: Capparaceae, Capparis herbacea, andromonoecy

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