Part 2, 1907] UREDINACEAE 115 
10. UREDINOPSIS Magn. Atti Congr. Bot. Genova 167. 1893. 
Cycle of development imperfectly understood; telia and two other spore-forms known, 
for convenience called aecia and uredinia. No evident alternating phases observed. Aecia 
and uredinia subepidermal, teliospores solitary, scattered in the mesophyl, segregated be-: 
neath the epidermis, or rarely within the epidermal cells. 
Aecia roundish, bullate, small, indehiscent. Peridium depressed-globoid, delicate, 
with polygonal cells above and elongate cells at sides, the lateral cells usually reinforced 
with shorter cells outside. Aeciospores borne singly on pedicels, but packed in sorus as if 
catenulate, obovate to globoid, angular, or polyhedral, rarely acute above; wall colorless, 
medium thick, thicker along the angles, minutely verrucose. 
Uredinia bullate, roundish, usually larger than the aecia, dehiscent by central rupture, 
from which the agglutinated spores are ejected in a long, white filament. Peridium more 
delicate than,in aecia, and often imperfect. Urediniospores borne singly on pedicels, fusi- 
form, acute or beaked above, narrowed below; wall colorless, thin, smooth, except two 
opposite, longitudinal, thickened ridges bearing single rows of minute projections, often 
invisible when wet. 
Teliospores globoid, one- to four-celled or more, usually with intersecting septa; wall 
smooth, colorless, thin. 
Type species, Uvedinopsis filicina Magn. (on Phegopteris vulgaris). 
Urediniospores echinulate on the two longitudinal ridges. 
Echinulations long, cilia-like ; beak very long. 1. U. Osmundae. 
Echinulations short, minute points ; beak medium long. 2. U. mirabilis. 
Urediniospores verrucose on the two longitudinal ridges. 
Sculpturing distinct, when seen dry. 
Papillae coarse, loosely set, often a few on face of spore ; beak very 
_ Short. 
Papillae fine, closely set ; beak usually short. 
Sculpturing obscure, even when dry. 
Papillae appearing as serrations; beak medium short, strong. 
Papillae fine, closely set ; beak very long, slender. 
Papillae very obscure ; beak long, strong. 
. U. Pteridis, 
. U, Copelandi, 
OU. Struthiopleridis. 
U. Phegopteridis. 
. U. Atkinsonit. 
NAN Bw 
1. Uredinopsis Osmundae Magn. Hedwigia 43: 123. 1904. 
Miulesia Osmundae Arth. Résult. Sci. Congr. Bot. Vienne 337. 1906. 
I, Aecia unknown. 
II. Uredinia hypophyllous on yellow spots, roundish, 0.2-0.4 mm. across, bullate, 
widely dehiscent by central rupture, spores exuded in a white filiform mass; urediniospores 
oval or fusiform, 13-18 by 36-57, acute or acuminate above with apex prolonged into a 
moderately strong, uniform beak, 8-20 long, often bent; wall colorless, thin, 1“, smooth 
except the two opposite longitudinal lines of delicate crowded cilia, 2-3 long. 
III. Teliospores segregated in and beneath the epidermal cells of both surfaces of the 
leaf, numerous, globoid or ellipsoid, 20-33 broad by 18-22 high, usually 4-celled, some- 
times 2-many-celled ; wall colorless, thin, 1-1.54, smooth. 
ON OSMUNDACEAE : : : ; 
Osmunda cinnamomea I,., Alabama, Maine, Massachusetts, New York, Wisconsin. 
Osmunda Claytoniana I,., Maine, New Hampshire, New York. 
Osmunda spectabilis Willd. (O. regalis L., in pt.), Wisconsin. 
TyPE LOCALITY: Cayuga Lake, New York, on O. cinnamomea, | 
DISTRIBUTION : Alabama to Wisconsin and northeastward to Maine. 
ILLUSTRATION : Hedwigia 43: pl. 2, f. 8-16. 
2. Uredinopsis mirabilis (Peck) Magn. Hedwigia 43: 121. 1904. 
Septoria mirabilis Peck, Ann. Rep. N. Y. State Mus, 25: 87. 1873. 
Tedinopsis americana Sydow, Ann. Myc. 1: 325. 1903. . 
Milesia mirabilis Arth. Résult. Sci. Congr. Bot. Vienne 337. 1906. 
I. Aecia hypophyllous, scattered, or somewhat gregarious, roundish, small, 0.1-0.2 
mm. across; peridium strongly developed ; aeciospores angularly obovate or polyhedral, 
15-20 by 24-36; wall colorless, medium thick, 2-3, thicker at the angles, minutely 
verrucose, 
