Twenty-fib ST Annual Meeting. 67 



On Sisymbrium officinale Scop. 

 1599, on leaves, June 18, 1889, Manhattan; 1657, on leaves, July 3, 1889, Manhat- 

 tan; 1530, on leaves, July 30, 1887, Lawrence. 



On Nasturtium Armoracia Fries. 

 1517, on leaves. May 20, 1885, Manhattan; 1504, on leaves, 1883; 1631, on leaves, 

 June 29, 1889, Manhattan (a Septoria occurs on the upper side of the spots caused 

 by the Cystopus); 446, on leaves, August 10, 1883, Manhattan. 



On Nasturtium, sessiliflorum Nutt. 

 M. A. Carleton No. 102, on leaves, May 18, 1888, Cloud county; 1521, on leaves. 

 May 22, 1887, Manhattan; 1503, on leaves, May 31, 1884, Zeandale, Riley county. 



On Capsella Bursa-pastoris Moench. 



1506, on stems, pedicels, and seed-pods. May 20, 1886, Manhattan; 1538, on stems, 

 pedicels, and seed-pods, June 6, 1889, Manhattan. 



On Brassica Nigra Koch. 

 1650, with very abundant mature oospores in the ends of the stems and pedicels, 

 and even flowers, causing considerable distortion, no conidia, July 4, 1889, Man- 

 hattan. 



On Lepidium, intermedium Gr. 



1536, on leaves, April 4, 1889, Manhattan; 1518, on leaves, April 5,1888, Manhattan; 

 1529, on leaves, April 5, 1889, Manhattan; 1665, on leaves, April 6, 1889, Manhattan; 

 1534, with mature oospores, on leaves, April 25, 1889, Manhattan; E. Bartholomew, 

 No. 293, with young oospores, on leaves, May 27, 1889, Rooks county (Peronospora 

 parasitica, No. 293a, also occurs on the same plants); 1522, with mature oospores, 

 on leaves, June 1, 1887, Manhattan. 



On Lepidium Virginicum L. 

 1505, with young oospores (?), on leaves, May 4, 1884, Manhattan. 



On Raphanus sativus L. (cult. Radish). 

 446a, on leaves. May 30, 1885, Manhattan. 



2. Cystopus Ipomoeae-panduranae (Schw.) Stevs. <fe Sw. ^cidium Ipomoeae-panduba- 

 NAE, Schw. Syn. Fung. Carol., No. 454. Caeoma (^cidium) Convolvdlatum, 

 Schw. Syn. Fung. Am. Bor., p. 292, No. 2866. Cystopus Convolvdlaceabum, 

 Otth. sec. Zalewski in Bot. Centralb., XV Band, (1883) S. 223. Cystopus Con- 

 voLVULi, Otth. (?). Cystopus Convolvulaceakum, Speg. (?) Fungi Guarantici, 

 Pug. I, No. 163. Cystopus cubicus, Auct., p. p. 



Conidia on leaves, petioles, stems, and calyces, and oospores only in stems,* 

 of Convolvidaceae June to September; most abundant during July and August. 



On Ipomoea hederacea J acq. 



1507. on leaves, June 11, 1886, Manhattan; 1635, on leaves, July 18, 1887, Mound 

 City; 1792, on leaves and stems, August 1, 1889, Manhattan; 1539, on leaves, August 

 15, 1887, Manhattan; 1540, on leaves, August, 1886, Manhattan; 1669, on leaves, stems, 

 and flowers, August 18, 1889, Stockdale, Riley county; 1520, (Coll. D. G. Fairchild,) 

 on calyces and leaves, September 6, 1887, Manhattan; 1879, with a few mature 

 oospores on stem just below calyx, September 28, 1889, Manhattan. 



On Ipomoea lacunosa L. 

 1765, on leaves, August 28, 1889, Manhattan. 



* Dr. B. D. Halsted sends me specimens collected on Ipomoea pandurata at Millstown, N. J., Sept. 3, 

 1889, which have many oospores in the leaf spots, and in swellings of the petiole. 



