Comparative pollen morphology of Glechoma and Marmoritis （Nepetinae, Lamiaceae）

• Published in: Journal of systematics and evolution : JSE 2010, Vol.48 (6), p.464-473
• Main Author: Tae-Soo JANG Suk-Pyo HONG
• Format: Article
• Language: English
• Subjects: 唇形科; 形态比较; 形态特征; 电子显微镜观察; 花粉形态; 薄荷属; 透射电子显微镜
• ISSN: 1674-4918; 1759-6831

The pollen morphology of 13 taxa （34 specimens） was investigated in detail using light, scanning electron, and of the genera Glechoma L., and Marmoritis Benth. transmission electron microscopy. Pollen grains of all studied taxa are small to large in size （P = 32.5-60.4 um, E = 20.2-50.5 um）, prolate-spheroidal to prolate in shape and mostly hexacolpate （the amb more or less circular or rarely ellipsoid） with granular membranes. The sexine ornamentation of Glechoma is bireticulate; the muri of the primary reticulum are irregularly circled, and lumen size is short. In contrast, the sexine surfaces of the Marmoritis pollen tend to more elongate or wider at the muff of the primary reticulum than those of the Glechoma. The pollen wall stratification of selected taxa （three from Glechoma and one from Marmoritis） is characterized by unbranched columellae, and continuous or distinctly discontinuous endexine based on transmission electron microscopy observation. The results of Glechoma and Marmoritis reveal rather similar pollen morphological features, however, fine details of sexine ornamentation are characteristic to differentiate the pollen taxa. Although these differences may be useful in establishing the taxonomic boundary between two genera, they are too weak to segregate diagnostic characters.