MICHIGAN ACADEMY OF SCIENCE. 53 



hent-e Winter must have had the species that has since been called Sclerotinia 

 fructigena. If the rule of priority is to apply to the species name first as- 

 sociated with the perfect stage, the correct name of this fungus is Scler- 

 otinia fructicola (Winter) Rehm instead of Sclerotinia fructigena (Pers.) 

 Norton. 



A NEW SPECIES OF SCLEROTINIA. 



Sclerotinia aestivalis Pollock n. sp. Since the preceding part of this paper 

 went to the printer a new species of Sclerotinia has been collected at Pal- 

 myra and Ann Arbor, Mich., first by Dr. L. H. Pennungton. June 26, 1909, 

 then by myself and several of my students through July and up to Aug. 9. 

 It occurs on old mummied apples that have lain on the ground over winter. 

 It is apparently not a parasite on either the apple or plum, since ascospores 

 inoculated into ripe and unripe apples both sound and bruised did not de- 

 velop a Monilia stage nor cause a rapid rot of the apples. Similar negative 

 results were obtained on inoculating the ascospores into plums. After 

 several weeks in the moist chamber a very slow rot on both takes place. 



Apothecia from one to fifty on a single mummied apple; stalks short, 

 rarely reaching one 1 cm., not more than .5 mm. thick, dark brown and 

 tapering below, lighter colored above; disc from 1-7 mm. in diameter, light 

 reddish brown, flat when mature, radiating ridges and furrows below, 

 not hairy but appearing almost velvety on outside; asci somewhat clavate 

 or nearly cylindrical, short for the genus 51-85 X 6-8.5 mostly 68-75 micro- 

 millimeters long, not turned blue by iodine, several from a common stalk 

 when teased out; ascospores narrowly elliptical, 6.4-11.9 X 2-3.4, average 

 size about 8.5-3 micromillimeters. 



This species differs from the other species of the genus occurring on 

 fruits in the time at which the apothecia develop. They are usually pro- 

 duced in April or ^lay while this one occurs in mid summer on account of 

 which the species name aestivalis is chosen for it. 



The conidial stage was searched for where the ascus fruits were found, 

 but none Avas found. Attempts were made to get cultures of the ascospores 

 as they were shot into the air, but no conidial stage developed. Whether 

 there is no conidial stage or whether the right conditions for its development 

 have not been offered is not at present ascertained. 



REFEREXCES TO SCLEROTINIA. 



Aderhold and Ruhland, Zur Kenntniss der Obstbaum Sclerotinien (1905). 



Abstract in Zeitschrift fiir Pflanzenkrankheiten. 16: 37. 1906. 

 Lindau, In Rabenhorst's Kryptogamen-Flora. Bd. 1 Abt. 8. p. 52. 1907. 

 Norton, Sclerotinia fructigena Trans. Acad, of Sci. St. Louis, 12: 91-97. 



1902. 

 Reade, Preliminary notes on some species of Sclerotinia. 



Annales Mycologici. 6: 109. 1908. 

 Saccardo, Sylloge Fungorum. Vol. 4: 34. 1886. Vol. 18: 1906. 

 Schroter, Die Dilze Schlesiens. Vol. 2: 67. 1908. 

 Woronin, Ueber Sclerotinia cinerea und Sclerotinia fructigena. 



Mem. de I'Acad. St. Petersbourg. Series VIII. Phvs-Math. Classe, 

 Vol. 10: 1900. 



