A new species of Puccinia onOcimum adscendens

Summary

• 1. The fungus attacks leaves and sometimes twigs. The infected portions appear as concentric blotches. Three spore forms,viz., pycnia, æia and telia are present.

• 2. Pycnia are subhypodermal-flask shaped and orange yellow in colour. The paraphyses are exserted from the ostiole.

• 3. Aecia are developed on both the surfaces of the leaves, and are covered with well-developed peridia. Aeciospores are polyhydral and smooth-walled. A single germ pore becomes visible during germination.

• 4. Telia are amphigenous and are black in colour. Teliospore is stipitate, and two-celled. Spores germinate without a period of rest. The basidiospores are thin-walled, and uninucleate. Some abnormal types of germinations have been described.

• 5. Basidiospores infect the same host and form pycnia and æcia, and thus it is manifest that the fungus is autœcious.

• 6. Spore measurements and other considerations goes to show thatAecidium leiocarpum Syd. is the æcial stage ofPuccinia leiocarpum (Syd.) Thirumalachar. In conclusion the author wishes to acknowledge his indebtedness to Dr. M. A. Sampathkumaran,m.a., ph.d., Professor of Botany, Central College, Bangalore, for guidance and encouragement in the course of this work, and to Dr. B. B. Mundkur, Imperial Agricultural Research Institute, New Delhi, for the help given in identifying the species and valuable suggestions.