The Explosive Pollination Mechanism and Mating System of the Weedy Hyptis suaveolens (Lamiaceae)

Abstract The flower of the perennial shrubby herb, Hyptis suaveolens (L.) Poit. is representative of an explosive pollination mechanism. The carinal structure formed by the middle lobe of corolla lower lip conceals the stamens and stigma and does not open following the natural anthesis. Upon anthesis, the carinal lobe is under tension which is later released by wind or bees. The violent explosion of the carinal lobe caused by wind results in self-pollination; by bees, it results in self- and cross-pollination. Foraging activity of some bees which collect pollen from the anthers and stigma on H. suaveolens may reduce the success of pollination.
The mating system involves both autogamy and allogamy. Both require explosion of carinal lobe for pollination. The flexibility of the mating system is considered a safeguard ensuring its ruderal nature for weediness.