Indication for the Presence of Mixed Modes of Sporogenesis in Lindsaea Heterophylladryand. (Lindsaeaceae: Pteridophyta)

Morphological studies on sporangia and spores of the hybrid fern Lindsaea heterophylla Dryand. (L. ensifolia Sw. x L. bonii Christ.) from South India indicates the presence of mixed mode of sporogenesis with the occurrence of 8 spored sporangia during peak winter (December) and 32 spored sporangia during late winter (January). This kind of reproductive flexibility in this fern is attributed to environmental adaptation. Both morphological and reproductive flexibility in this species also proved the hybrid origin of this species. Further cytogenetical studies are required on this hybrid fern along with its parents to confirm the ploidy level of this fern, Lindsaea heterophylla Dryand.