40 
Mycologia 
A New Species of Colletotrichum on Asclepias 
My attention was called to an interesting anthracnose of As- 
clepias speciosa by Mr. W. W. Jones, botanist in the laboratory 
of plant pathology, department of agricultural investigations, 
American Smelting and Refining Company. Upon careful study 
of the disease, it was found that a new species of Colletotrichum, 
more or less intermediate between Gloeosporium and Colletotri- 
chum, proved to be the causative agent. It is interesting to note 
that this new species of Colletotrichum produces very few setae; 
very often they are entirely wanting. The fungus attacks both 
the foliage and the stems, producing characteristic irregular spots 
on the foliage and most often a complete girdling of the stems 
near the base. The spots on the stems when not confluent are 
more or less elliptical. The conidial masses on both foliage and 
stems are distinctly salmon-colored in fresh specimens. Diseased 
plants are easily noted by the premature yellowing of the foliage. 
A more complete description will be presented later when the 
cultural work has been completed. The description of the spe- 
cies is as follows : 
Colletotrichum salmonicolor sp. nov. 
Maculis in caulibus et foliis, brunneis, atro-brunneo-marginatis. 
Maculis in foliis amphigenis, irregularibus, leniter depressis, 2-6 
mil. diam., saepe confluentibus. Maculis in caulibus, lenticulatis, 
saepe confluentibus, initio leniter depressis, deinde elevatis, 2-7 
mil. long. Acervulis amphigenis, sed in hypophyllo copiosoribus, 
minutis, numerosis, irregularibus, elevatis, dense aggregatis inter- 
dum confluentibus, initio epidermide velatis, dein erumpentibus, 
massa conidiorum salmonicoloratis erumpente ; conidiis subhya- 
linis, granulosis, 2-4 guttulatis, irregularibus, rectis vel levissime 
curvatis, saepe ad basim leviter attenuatis et summo rotundatis, 
5-6X17.5-35 /«.; basidiis hyalinis, granulosis, conidio subaequi- 
longis ; mycelio parce vel non septato ; setulis erectis, sparsis, 
panels, saepe nullis, superne acutis 1.5 /a crassis, inferne g/x cras- 
sis, 2-3 septatis et 75— 105 longis, rectis vel leniter curvulatis, 
saepe nodulosis, atro-fuligineis vel brunneis, cellula inferior! sub- 
hyalina. 
Hab. in caulibus et foliis vivis et languescentibus Asclepiadis 
speciosae. Salt Lake Valley, Utah, Amer. bor. 
