SCANNING ELECTRON-MICROSCOPE OBSERVATIONS ON ZOOSPORANGIAL ABSCISSION IN PHYCOPELTIS-EPIPHYTON (CHLOROPHYTA)

Zoosporangial abscissin in asexually reproductive Phycopeltis epiphyon, Millardet, epiphytic on leaces of Osmanhus fragrans Loureiro and Sabal minor (Jacquin) Person, examined with scanning electron micrsscopy is described and compared with the process in related Cephaleuros virescens Kunze. The laeral wall of he zoosporangium‐pedicel septum begins to rupure early in he abscission process and is followed by continued learing of the lateral wall and partial spliing of the septum. The zoosporangium remains attached in a hinge‐like fashion to the pedicel by a portion of the lateral wall and septum. A centrally located protuberance emerges from wihin the septa of both the zoosporangium and pedicel, and together with a slight bulging of the septa, is involved in the final separation of the zoosporangium. Although there are differences in surface morphlogy of identical in P. the zoosporangia and the location of the exit pores, the process of abscission is identical in P. epiphyton and C. virescens. Copyright © 1978, Wiley Blackwell. All rights reserved