Additional Notes on Spore Morphology of Two Huperzia (Lycopodiaceae) Species and Systematic Significance

摘要

An additional note on spore morphology of two important species of tassel ferns viz. Huperzia phlegmaria (L.) Rothm. and Huperzia squarrosa (G. Forst.) Rothm. from Manipur (North East India) are presented and compared with the existing literatures. Some key spore parameters are newly highhghted through Scanning Electron Microscopic studies and presented elaborately in the present study. Spore in both the species are remarkably similar to one another and rather indistinguishable at first glance. Theyare triangular to sub-triangular in outline, trilete in nature with sides straight to somewhat concave margins. Distal spore surface shows foveolate ornamentation while proximal surfaces are unornamented in both the species. The two species differ in having more number of pits or depressions separated from one another between (0.5-1) am with broader ridges of (5-7) um diameter in Huperzia phlegmaria while the pits are sparsely distributed in between (0.5-3) um with narrower ridges (>3 jim diameter) in Huperzia squarrosa. The undulations on distal surface in between the pits are more prominent in later species. In contradiction to earlier view of categorizing the two species under Phlegmaria (H. phlegmaria) and Selago (H squarrosa) type, the present findings supported that both spores are assumed to be closely related to one another with common phylogeny and can be categorized as same spore type. The study also depicts the immense significance of sporal parameters in accurate circumscription of taxonomic status.