10 



Mycologia 



atris, 500-600 fx diam. ; conidiis magnis, hyalinis, dense granulosis, 

 interdum guttulatis, cylindraceis v. leniter clavatis, 3-septatis, 

 72-115X13-15^ 



On living leaves of Agave Americana L. Austin, 1283 {type) ; 

 San Antonio, 1377; Boerne, 164.8. 



The blight begins at the tips or margins of the leaves and ad- 

 vances toward the base. The diseased tissue becomes dry, gray, 

 and zonate, marking the periodic growth of the fungus. The 

 pycnidia are on both leaf surfaces, covered at first and at length 

 protruding. Our species differs from 5". macrospora (Dur. & 

 Mont.) Sacc. in having much larger spores and also larger 

 pycnidia. This disease has been very serious, blighting the plants 

 in all the localities where it was observed. 



Colletotrichum caulicolum 



Acervulis sparsis, nigris, lenticularibus, 150-250 /x. Setis 

 copiosis, brunneis, septatis, utrimque rotundatis vel superne 

 acutis, 6o-i2oX3-5-4/*; basidiis 30-60//,, cylindraceis, hyalinis, 

 plerumque 1-2-septatis ; conidiis falcatis, hyalinis, granulosis, 

 18-30 X 3-5-4/*- 



On living stems of Phaseolus vulgaris L. Uvalde, 1963 

 {type). 



A destructive disease of the Kentucky Wonder bean, observed 

 in a single locality, was found to be due to this fungus. A super- 

 ficial examination of the affected field showed a considerable 

 number of plants which were completely dead, others were dying, 

 while still others that were less affected exhibited more or less 

 chlorosis of the foliage. An examination of the root system 

 showed it to be in normal condition, while the only deviation from 

 the normal in the foliage was the marked chlorosis. 



An examination of the stems showed that brown, depressed 

 cankers were present an inch or more above the ground level. 

 The cankers were longitudinally elongated (2-4 cm.), more or 

 less irregular, rough and somewhat fissured or open. On the 

 chlorotic plants the canker occupied one side of the stem, on the 

 plants that were dying the stem was nearly girdled, and on all 

 dead plants examined the canker had completely encircled the 

 stem. 



