Some new or interesting Physoderma species from India. II.

Abstract

India. H. By M. S. Pavg i & M. J. T h i r u m a l a c h a r , (Banaras Hindu University and Malleswaram Bangalore, India.) ..,-.. :...-. : . ; , With plate IV—V. ..},,. In a recent paper (1954) the writers described some of the interesting species of Physoderma collected from different parts of India, including two new species, Ph. dichanthicolum and Ph. brachiariae. The study of Physoderma species have evoked considerable interest, primarily because it is a member of the chytriaceous group, and secondly of their rarity and interesting life-cycle. Their rarity may to some extent be due to the fact that many of the species incite very incospicuous Symptoms and are easily overlooked in the field. Few others such as Ph. alfalfae, Ph. aeschynomenae and Ph. limnanthemi though incite conspicuous gall formations, are either subterranean or produce galls in submerged parts of the plant, so that it is by accident that one comes across with these forms. All collections of materials f or the present study have been made in the neighbourhood of the Banaras Hindu University. As was pointed out in previous paper, species of Physoderma are most commonly met with in particular habitats. They are mostly found in low lying patches in the fields which become water-logged during the rainly season between July to September. The plants that are submerged become exposed during September-October when the small puddles begin to dry up. In species such as Ph. aeschynomene the region of infection on plant become specifically demarcated to the submepged parts only. In the present study accounts of seven species of Physoderma are presented. They all produce inconspicuous spots on the hosts and none of them incite systemic infection. The type specimens of the new species have been deposited in the Herb. Crypt. Ind. Orient., New Delhi, Herb. C. M. L, Kew, England and Mycological Division, U.S.D.A., Beltsville, Maryland, U.S.A.