Definition of protandrous in English:
protandrous
adjective prəʊˈtandrəsprōˈtandrəs
Zoology Botany (of a hermaphrodite flower or animal) having the male reproductive organs come to maturity before the female.
The opposite of protogynous
Example sentencesExamples
- The flowers are protandrous, and larger plants have a lower pollen to ovule ratio than smaller plants, suggesting larger plants invest proportionally more in female function.
- Perfect flowers are protandrous, hence the stigmas open after anthesis, which reduces the probability of autogamous self-pollination.
- The flower is protandrous and presents an unusual sophisticated morphology: the pistil has an umbrella shape with the stigma at the angles, tightly enclosed by the bracts, petaloid sepals and petals.
- It is a wind-pollinated species, with hermaphroditic protandrous flowers (the first two days as male and three last days as female).
- In many protandrous spiders, adult males cohabit with juvenile females nearing sexual maturity, and this may provide an index of expected mate availability for females.
Derivatives
noun
Botany Zoology Flowers are self-compatible, but spontaneous autogamy occurs very infrequently due to protandry and to the spatial separation of anthers and stigma.
Example sentencesExamples
- Predictions from the above hypotheses are not mutually exclusive, and associations between protandry and sexual dimorphism may be promoted by complex interactions between the suggested mechanisms acting in concert.
- The sex ratio at emergence was 1: 1, and protandry was evident.
- The temporal aspects of stigma receptivity and pollen longevity were investigated in relation to protandry (the occurrence of anther dehiscence prior to stigma receptivity) and breeding system.
- Under natural photoperiodic conditions protandry in hermaphrodite disc flowers of sunflower is determined by the different elongation rates of the style and filaments.