64 Witson: NortTH AMERICAN PERON ALES 
Oéspore with numerous small tubercles; conidial 
embrane with an equatorial thickening. 4. A, [pomoeae-panduranae, 
Oéspore finely echinulate; conidia dissimilar, the 
terminal larger. . A, Lepigoni, 
Oéspore reticulate (unknown in nos. 8 and 9); conidia cylindric or elliptic, usually 
longer than broad, if discoid the membrane with an equatorial thickening. 
Odspore with the areolae unoccupied ; conidial membrane with an equatorial 
thickenin 
Oédspore coarsely reticulate ; conidia elongate. 
OS sth +h 2 1 bd Pes | Load 1 
ir angles; conidia cylindric, 
or with more or less rounded corners, hyaline, the terminal larger. 
Conidial membrane always with an equatorial thickening. 
Conidia more or less rounded ; 
hosts Gentianaceae. . A, Swertiae. 
Conidia cylindric; hosts Com- 
positae. 7. A. Tragopogonis. 
Conidial membrane of the terminal 
conidium only with an equatorial 
thickening. . A, quadrata. 
Oéspore without tubercles; conidia obo- 
void or elliptic. 
Conidia obovoid, the terminal larger. 9. A. Zi//aeae. 
Conidia elliptic, the terminal smaller. 
Conidia uniformly hyaline. 
Conidia light-yellow, the termi- 
nal with a dark equatorial 
10. A. Biiti. 
and. 11. A. platensis. 
Oédspore finely and shallowly reticulate, appear- 
ing pitted; conidia discoid, yellow. 
Céspore with a tubercle in each areola; conidia 
cylindric, the membrane of uniform thickness. 13. 4. Portulacae. 
ca 
te 
. A. occidentalis. 
1. ALBUGO CANDIDA (Pers.) Kuntze, Rev. Gen. Pl. 
a: G68... 1891 
Aecidium candidum Pers. in Gmelin, Syst. Nat. 27: 1473. 1791: 
Uredo candida Pers. Syn. Meth. Fung. 223. 1801. 
Uredo Chetranthi Pers. Syn. Meth. Fung. 224. 1801. 
Cystopus candidus Lév.; Berk. Jour. Hort. Soc, London 3: 271: 
1848. 
Sori on all parts of the host except the roots, white or rarely 
light-yellow, prominent and rather deep-seated in the tissues of the 
host, very variable in size and shape, often confluent and frequently 
producing marked distortion of the host; conidiophores hyaline, 
clavate, about 35-40 x 15-172; conidia similar, globular, hyaline, 
with uniform thin walls, 15-18 #4; odspores usually confined to the 
stems and fruits of the host, rarely in the leaves, chocolate-colored, 
