囊萼紫草属与滇紫草属花粉形态比较研究

本文借助光学显微镜和扫描电镜研究了囊萼紫草属3种和滇紫草属12种植物的花粉形态。囊萼紫草属的花粉为哑铃形或茧形，中等大小，P／E比为1．6一1．67，三孔沟，内孔横长；具小刺状纹饰。滇紫草属的花粉为近长球形或近卵球形，P／E为l—1．23；三孔沟或三合沟孔，内孔一般纵长，具皱波状纹饰，在皱波上具密集的小瘤或微颗粒。从花粉形态的角度，本文支持把囊萼紫草属从滇紫草属(广义)中分离出来的观点。值得注意的是，在滇紫草属的花粉中首次观察到了一种比较少见且特化的花粉即单极三合沟孔的花粉。

A COMPARATIVE PALYNOLOGICAL STUDY ON THE MAHARANGA AND ONOSMA (BORAGINACEAE)

Pollen morphology of three species in the genus Maharanga and 12 species in the genus Onosma , belonging to the family Boraginaceae, was examined by means of light microscope and scanning electron microscope. Pollen grains of the genus Maharanga are dumbbell-shaped or cocoon-shaped, medium-sized, P/E 1. 6-1. 67 ratio, tricoporate with lalon-gate ora,and spinulate,while those of the genus Onosma are subprolate or ovoid, P/E 1-1. 23 ratio, tricolporate or trisyncolporate with lolongate ora, rugulate-microgranulate or tubercu-late. The pollen morphology supports the separation of the genus Maharanga from the genus Onosma (sensu la to). Noteworthily, the three colpi of syncolporate pollen in some members of the genus Onosma converge in one pole or even two poles.