Population Structure and Reproductive Biology of Saururus cernuus L. (Saururaceae)

Abstract

The population structure and reproductive biology of Saururus cernuus (Lizard's Tail; Saururaceae; Piperales), is documented in five sites in southern Louisiana (Mississippi Delta). The species is common throughout the southeastern United States in marshes, along streams, edges of lakes, and in the understory of moist forests. The clonal species exhibits sexual and vegetative reproduction. Wind and insects both play important roles in pollination. Pollen may be borne by insects directly. Alternatively, the pollen may be borne by wind after its release is triggered from pendulous floral spikes (the “Lizard's Tail”) by either wind or insect landings (insect-mediated wind pollination). The plants are self-incompatible and seed set results from a combination of pollination modes with wind pollination being the primary mode (rare in the Magnoliidae). Inflorescence and floral structure exhibit adaptive features that facilitate the various modes of pollen transfer, viz., numerous, small scented, protogynous flowers with no perianth, ultraviolet patterns produced by stamen filaments, small pollen grains, curved inflorescences, and exerted stamens, etc. Fruit production and seed germination are documented and plant growth and densities are compared in sunny versus forest sites.