152 



nuts Pyrolce, Ell. and Hals. Tlie color of the hyphae of this spe- 

 cies is a distinct cinnamon, and forms a thick felt-like covering 

 upon the stem, beginning at the surface of the ground and ex- 

 tending up for about two inches. The whole genus may be con- 

 sidered as a chromatic one, for nearly all colors are represented, 

 as the following names of some of the species will indicate: Z. 

 fusctis^ Z. atro-rithcr, Z. violacco-fuscns, Z. riibiginosns, Z. ferru- 

 gtncus, Z, olivascenSj Z. ochraceus, there being two species of the 

 latter in Saccardo ! 



Within the past month another species has been found, and 

 this one has all the characteristics of a genuine parasite, which was 

 not so evident in the Pyrola species. While inspecting a bed of 

 cultivated violets under glass for the leaf spot fungus [Cercospora 

 ViolcE, Sacc), Botrytis and other fungi, It was a surprise to find 

 several leaves upon a few plants in a group covered with a. chalky 

 white coat, reminding one somewhat of the Erysiphea^, but with- 

 out the powdery appearance. A microscopic examination of 

 the infested parts of the leaves showed that the characteristic 

 threads of the Zygodesmus, easily recognized by the excessive 

 branching and lateral union of adjoining cells in the hyphie, were 

 all through the tissue of the liost, and had caused the affected 

 parts to lose their green color. A thick mat of hyplue had 

 formed upon the surface, and threads could be traced from this 

 through the breathing pores to the ramifications within. Upon 

 leaves long infested the tissue becomes dry and contracted, and a 

 cream color replaces the almost pure white. That the species is 

 not confined to the violet is demonstrated by finding a few sprays 

 of parsley growing in the vicinity of the attacked violets, aflllicted 

 by the ^'Ci.vi\<t Zygotic sinus and whitened almost as if sprayed with 

 a lime-wash. 



Besides adding a well established parasite to the genus which 

 is generally held as saprophytic, the violet specimens reach another 

 step in the chromatic scale, and naturally the species has been 

 named Z albidus^ Ell. & Hals, and will probably be distributed 

 in the Ellis North American Eungi. 



BVRON D. Halsted. 



Ru KJCRS CuLLFx^E, April iS, 1890. 



^Syllu-c Fungorum, Vol. iv. pp. 283-28S. 



