The Species of Ciborinia Pathogenic to Salix, Magnolia, and Quercus

Abstract

BATRA, LEKH R. (Swarthmore Coll., Swarthmore, Pennsylvania.) The species of Ciborinia pathogenic to Salix, Magnolia, and Quercus. Amer. Jour. Bot. 47(10): 819-827. Illus. 1960.There are 2 species of Ciborinia that attack various species of Salix. One of these, C. wisconsinensis, is reported as new and its phytopathology and life history are discussed. This species forms sclerotia in the leaves along the midrib. The sclerotia germinate in the year following infection and form apothecia in late June. In culture, sclerotia formed from mass ascospore-shootings produce apothecia. Ciborinia candolleana is reported for the first time attacking Quercus spp. in the United States. A key to the known species of the genus Ciborinia is provided. THIS study of the genus Ciborinia Whetzel is a continuation of previous work (Batra and Korf, 1959). Most of the species of Ciborinia attacking woody angiosperms form sclerotia along the vascular bundles, primarily encircling the midrib and the major veins. Generally the selerotia are formed late in the season, after the leaves have fallen on the ground. With the exception of one species, C. violae Batra and Korf, the species of Ciborinia attacking herbaceous angiosperms form sclerotia scattered all over the leaves while they are still green and attached to the plant. 'Received for publication February 2, 1960. The research was supported by a grant from the Penrose Fund of the American Philosophical Society. The author wishes to acknowledge with thanks the loan of herbarium material from Dr. Clark T. Rogerson, New York Botanical Garden, and Mr. John A. Stevenson, The National Fungus Collections. Dr. William C. Denison, a colleague, was very helpful in seeking materials as well as devoting time to discussion of this research. Professor N. F. Buchwald of Copenhagen was very generous in loaning European collections of Ciborinia candolleana for comparison. The author is indebted to Dr. R. P. Korf for critical reading and editing of the manuscript. The work on which this paper is based was in part carried on in the Department of Plant Pathology, Cornell University, Ithaca, N. Y. The materials investigated and the methods employed are essentially the same as reported earlier (Batra and Korf, 1959). Starbick's (1895) concept of discomycete tissue anatomy elaborated by Korf (1951, 1958) has proved to be very useful in classifying the species of Ciborinia. Most of the work reported here was done at Cornell University during the period 1956-59. Although no extensive study was made of the species attacking, Populus L., they are being included in the following key and the reader is referred to the critical study done by Groves and Bowerman (1955). Four species, Ciborinia foliicola (Cash and Davidson) Whet., C. wisoonsinensis, a new species, C. gracilipes (Cooke) Seaver, and C. candolleana (Lev.) Whet. are described in detail. Ciborinia hirtella (Boud.) Batra and Korf, not so far recorded from the United States, is also included in the key. All the material pertaining to this research is deposited in the herbarium of the Department of Plant Pathology, Cornell University (CUP), Ithaca, N. Y. Names of the herbaria where the specimens referred to in this paper are located are taken from Lanjouw and Stafleu