1885.] 



NORTH AMERICAN CERCOSPOR^. 



Hyphse amphigenous, scarcely tufted, about equaling the length of the 

 conidia, which are rather large, narrowed upwards, greenish, four to six- 

 septate, 55—80 IJ- long, about 12 broad in the widest part. 



On living leaves of Datura stramonium^ June, Isf. Y. (Peck.) 

 (111.) Cercospora longispora, Pk. 35th Rep. N. Y. State Mus. 



Spots suborbicular, sometimes confluent and irregular, grayish-brown, 

 the margin slightly darker. Hyphse amphigenous, sometimes epiphyllous 

 only, tufted, 20 — 40 P- long, colored. Conidia very long, variously curved 

 or flexuous, colorless, simple or obscurely septate, sometimes forked, 60 — 

 170 long, about 4 broad. 



On living leaves of Lupinus perennis^ July, N. Y. (Peck.) 



The species is apparently very distinct from C. Lupini, Cke., and is 

 well marked by its densely tufted, black hyphse and its very long, hyaline 

 conidia. 



(112.) Cercospora varia, Pk. 35th Rep. Y. State Mus. 



Spots suborbicular, sometimes large and irregular, reddish-brown, 

 with a darker margin, reddish-gray beneath. Hyphse few, hypophyllous, 

 tufted, short, slightly colored. Conidia subcylindrical, one to five-sep- 

 tate, sometimes multinucleate, 40—70 p- long. 



On living leaves of Viburnum aceri/oUum, July, IS". Y. (Peck.) 



A form of this species occurs on Viburnum Lentago. In it the spots 

 are brown and the hyphse are shorter. Doubtfully distinct from C. tinea, 

 Sacc. 



(113.) Cercospora Comari, Pk. 35th Rep. State Mus. 



Amphigenous but more perfectly developed below. Hyphse elon- 

 gated, 150 — 200 X 3 — 4 continuous or with an occasional septum, genie, 

 ulate and bent above, reddish-brown, collected in little fascicles which 

 appear under the lens like a thin, erect, brown pubescence. Conidia 

 clavate, dark brown, about 5-septate, sometimes constricted at the septa, 

 40—60 X 6—8 IJ-. The fungus first appears in little brown patches (not on 

 definine spots) which soon become darker and spreading, become conflu- 

 ent and blacken the greater part of the leaf. 



On Potentilla palustris, New York (Peck.) 

 (114.) Cercospora Alismatis, Ellis & Hoi way, n. s. 



Spots indefinitely limited, brown, becoming whitish or gray in the 

 center, of irregular shape, i— 1 cm. Hyphse tufted, epiphyllous, dark 

 brown, continuous, abruptly bent, subnodulose and subdentate above, 50 

 —75 X 5—6 /J; Conidia hyalir.e, slender, gradually attenuated above, 5—9 

 septate 60—120 x 3—4 u-. 



On Alisma Plantago, Decorah, Iowa, July (Holway.) 

 (115.) Cercospora personata, (B. & C.) {Gladosporium personatum 

 B. & C. Grev., Ill, p. 106.) 



Forming small brown, orbicular spots (2— 4 mm.) on the lower sur- 

 face of the leaves. Hyphse densely tufted, short, brown, continuous. 

 Conidia mostly clavate, pale brown, about 3-septate, 30—50 x 5—6 p. 

 Originates beneath the epidermis. 



