LM and SEM pollen studies in Indian Alangiaceae

Abstract

The pollen grains of Indian Alangium Lam. Show interesting morphological features. In the present paper, the pollen of four species, viz., Alangium alpinum (Clarke) Smith, A. barbatum (R. Br.) Baill, ex Kuntze, A. chinense (Lour.) Harm. and A. salvifolium (L.) Wangerin have been studied under light and scanning electron microscopes. Alangium alpinum distributed in the eastern Himalaya, has 3-4 colporate pollen with characteristic striate sculptured exine. Whereas, A. chinense is distributed throughout the Himalaya as well as the plains has regulate-reticulate sculptured exine with aperture similar to A. alpinum, A. barbatum is sporadic in Assam and has 3-colporate pollen with faint striate sculpturing. A. salvifolium happens to be the most widely distributed species extending from Himalayan foothills to extreme south of the Indian Peninsula as well as Andaman Island and has 3-6 porate-porate-brevicolporate apertures. Pollen grains of A. salvifolium subsp. Sundanum (Miq.) Bloembergen show gemmate-granulate sculpturing whereas, in A. salvifolium subsp. Salvifolium (L.) Wangerin the sculpturing is regulate-verrucate-gemmate-granulate. SEM studies reveal secondary ornamentation in A. alpinum, A. barbatum and A. salvifolium and interesting variations in the orientation of muri in case of A. chinense.