Two new species ofDidymopsora from India

Summary

In the present paper an account of the morphology and life-history of two new species ofDidymopsora, D. Toddaliæ, andD. macrospora is presented. The rust is parasitic on the leaves ofToddalia aculeata var.gracilis andfloribunda.

The rust onToddalia aculeata had previously been identified by Petch asAecidium Toddaliæ, and later on changed toUredo Toddaliæ. Sydow in 1920 transferred the rust to the genusCtenoderma established by him asC. Toddaliæ (Petch) Syd. He mistook the urediospore; for the teliospores. Mains who merged the genusCtenoderma withSkierka, suggested that the rust onToddalia might be a species ofSkierka. In the present investigation, the telia have been observed, and the rust has been placed in the genusDidymopsora.

Pycnia are intraepidermal, applanate, without conspicuous ostiolar paraphyses. Uredia are subepidermal, and the urediospores are stipitate, with characteristic lateral ridges at the sides and at the apex.

Telia are exserted out in shortCronartium- like columns, and the spores are two-celled, sessile, hyaline, with a single distinct germ pore in each cell and germinating immediately. Telia have not been observed forDidymopsora macrospora.