• N Punetha

      Articles written in Proceedings – Plant Sciences

    • Cytological observations on some species ofPteris L. from Kumaon (northwest Himalaya)

      N Punetha Abha Sen

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      The paper deals with the cytology of 10 taxa of 8 species of the genusPteris L. from Kumaon in northwest Himalaya.Pteris biaurita andPteris dactylina are apogamous triploids (n=87),Pteris excelsa andPteris quadriaurita are sexual diploids (n=29), whereasPteris vittata is a sexual tetraploid (n=58) andPteris stenophylla is an apogamous diploid (n=58).Pteris cretica is represented by diploid (n=58) and triploid (n=87) apogamous races.Pteris wallichiana is normally sexual diploid (n=29) but an apogamous diploid (n=58) form from this area is a new record. Sexual mode of reproduction is observed in 40% taxa whereas 60% are apogamous.

    • Ecological and phytogeographical observations on the fern flora of Pithoragarh district (north-west Himalaya)

      N Punetha

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      A detailed account of ecology and phytogeography of the ferns of Pithoragarh district of Kumaon (north-west Himalaya) is discussed. Common mesophytic ferns are the species ofAdiantum, Athyrium, Cheilanthes, Christella, Dryopteris, Lygodium, Osmunda, Pseudocyclosorus andPteris. Polypodiaceous ferns are either epiphytes or lithophytes.Ceratopteris thallictroides is the only aquatic fern. From phytogeographical point of view it is observed that on the one hand the fern flora of this region bridges the floristics of eastern and western Himalaya, and on the other it resembles much with the fern flora of south China. About 70% ferns are common with Simla hills and 85% with Darjeeling and Sikkim himalaya.

    • Vascular morphology of stipe and rachis in some western Himalayan species ofPteris Linn.

      N Punetha

      More Details Abstract Fulltext PDF

      Vascular supply to leaf in 8 species of the fern genusPteris is described. Except inPteris cretica in which the stipe is supplied by a pair of ribbon like vascular bundles, stipe vasculature of the other 7 species studied is solitary and gutter-shaped; in transection the vascular bundle inPteris cretica, Pteris dactylina andPteris stenophylla is V-shaped, Ω-shaped inPteris wallichiana and horse-shoe shaped in others. InPteris vittata andPteris wallichiana pinna trace is extra marginal in origin while in all others it is marginal. Based on number and structure of vascular strand and nature of origin of pinna traces it is concluded thatPteris cretica andPteris vittata are relatively advanced over other species with simply pinnate fronds.Pteris wallichiana has been considered as highly evolved among the species investigated.

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