New insights into the pollen morphology of the genus Mutisia (Asteraceae, Mutisieae)

TELLERIA, M. C.; KATINAS, L.

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Lugar: Wien; Año: 2009 vol. 280 p. 229 - 241

0378-2697

The pollen morphology from 67 collections representing 52 species of Mutisia was analyzed by means of light, scanning electron and transmission electron microscopy. Pollen of Mutisia is comparable to that of the more widespread type found in Mutisiinae. The large sized pollen grains of the genus are characterized by the spheroidal-subprolate to prolate shape, large size, tricolporate aperture, with mesoaperture, exine Mutisia type, with sculpturing microechinate to rugulate or microechinate-rugulate. This basic pollen type is very variable in size, endoapertures shape, and exine thickness of the pollen grains. A new type of arrangement of columellae was observed in pollen of Mutisia section Mutisia (e.g. M. stuebelli, M. microphylla, and M. sodiroi). It is suggested that it might have harmomegathic significance. The pollen morphology and the polymorphism are discussed with regard to functional mechanisms and possible evolutionary significance.