95 



A New White Smut. 



While making a study of the parasitic fungi of the cultivated 

 spinach [Spinacea oleracea) it was a surprise to find a species of 

 Entyloma, and especially as this host is so distant in the natural 

 classification of plants, from any other host of a white smut. 

 The infected leaves had lost all their normal green color and were 

 of a pale yellowish white shade^in fact, presented much the 

 same appearance as succulent foliage may take on after having 

 been frost bitten some time before. Upon a closer examination, 

 however, the surface of the whitened leaves was found coated in 

 spots with a fine light substance that under the hand lens was 

 seen to be in minute tufts. The low power of a compound mi- 

 croscope revealed these miniature rosettes as consisting of slender 

 filaments bearing acicular bodies at their tips. Thin transverse 

 sections of these infected patches showed small clusters of spheri- 

 cal spores imbedded in the leaf tissue, but close to the under epid- 

 ermis. Further study demonstrated the fact that the clusters — 

 each consisting of from a dozen to fifty spores, were located 

 directly below the breathing pores and occupied the large inter- 

 cellular spaces there found in the loosely constructed succulent 

 leaf of the spinach. Placing a piece of the infected leaf, after 

 being cleaned by alcohol and potash, with the underside upper- 

 most and focussing, it was an easy matter to pass by optical .sec- 

 tions from the highest part of the conidial bearing tuft to the 

 center of the cluster of spores below. Carefully made sections 

 through the breathing pores bearing the fungus illustrated the 

 same disposition of the parts as seen in a side view. The 

 threads of the fungus are exceedingly minute, and the coni- 

 dia are so small and slender that they are easily overlooked 

 unless high powers are employed. It gives me pleasure to dedi- 

 cate the species to Mr. J. B. Ellis, who has done so much for the 

 cause of mycological study in this country. The following is a 

 description of the white smut of the spinach. 



Entyloma Er,LTSil. Spots pale white, indefinitely limited, 

 sub-confluent; spores globose nearly colorless i6-20/< in diameter, 

 'clustered in the intercellular spaces beneath the stomata. Co- 

 nidia hypophyllous, abundant, acicular, small I0-I4by less thani/'. 

 On cultivated spinach growing in hot beds near Newark, New 

 Jersey, January lO, 1890. 



