Pollen Morphology of Himalayan Viola (Violaceae)

  • K K Shrestha Central Department of Botany Tribhuvan University, Kirtipur, Kathmandu
  • K N Paudyal Central Department of Geology Tribhuvan University, Kirtipur, Kathmandu
  • D K Ferguson Department of Palaeobotany University of Vienna, Vienna,

Abstract

Pollen of 15 species of Viola L. (Violaceae) from the Himalaya were investigated by light and scanning   electron microscopy. The pollen of Viola are prolate-spheroidal to prolate, rarely oblate, 3 (4-5)-colporate, having a delicate exine with microvermcate ornamentation. Four types of pollen grains are recognized: (1) Viola hookeri me, characterized by subprolate to prolate grains, sexine microechmate to microvermcae and distinct perforations, (2) Viola pogonantha Type, prolate-spheroidal to prolate pollen, circular in outline in polar view, microvermcae uniform, not forming clusters, without dstinct perforations, (3) Viola pilosa Type, prolate-spheroidal to prolate, sexine rnicrovenucate, in clusters, perforations mostly inconspicuous, and (4) Viola tricolor me, pollen grains large (38-51 mm), oblate, stephano (4-5) colporate, mimvenucae comparatively large, nearly uniform, perforations inconspicuous (V. tricolor). The pollen morphologcal data suggest a rearrangement of species at the sectional level.