Usha di: I understand that the shape/structure of galls is determined by factors such as the plant part in question, stimuli from the gall-making organism and the response from the host plant. This one is a leaf gall formed probably by Aceria pongamiae mite: http://en.wikipedia.org/wiki/File:PongamiaPinnataGall.jpg
The globose structures are probably of floral-galls as they are seen in panicles. I couldn't find much detail on net for this. Chitra ji may have a better explanation.
Vijaya: please bear with me, and explain... how come an infection has proper branching pattern and looks like they are replacing some normal structure like a flower bud and bunches of them are hanging?? .. I know these round things are not pongamia fruits they look like this see attached file...
Chitra ji, those spherical structures are not fruits. The following note from my book:
"Note: Two types of galls are commonly observed: one with elongated
swellings on leaf-surface, said to be caused by Eriophyes cheriani Massee;
and the other with globose, hard, 5-8 mm dia., spherical structures that are often mistaken for normal fruits, reported to be caused by Asphondylia pongamiae Felt. (Mani, 1965)."
Vijayasankar Raman National Center for Natural Products Research University of Mississippi
I really doubt if they have globular fruits coz this being pushed as a biodiesal tree a lot of work jas been done on genetic variability. May be its drying of flower buds. I seem to see scale encrustations on the twigs which could have caused the drying
Dr. Chitra Shanker Sr. Scientist (Entomology) Directorate of Rice Research, Rajendranagar, Hyderabad -500030