BARTRAM: TORTULA IN SOUTHERN ARIZONA 339 
TORTULA AUREA sp. nov. (PLATE 6). Probably dioicous, 
male flowers not found, female flowers terminal or lateral by 
innovations, archegonia numerous, usually shrunken and unferti- 
lized, with slender paraphyses. Plants robust, 1 to 2 cm. high, 
branched above or simple, in deep rather loose cushions, yel- 
lowish green above, light brown beneath, sparingly radiculose. 
Leaves spirally twisted when dry, erect spreading when moist, 
ovate lanceolate, tapering above to a sub-acute apex, about 2 
mm. long, cuspidate by the stout excurrent costa which is occa- 
sionally prolonged into a smooth yellow hair point half as long as 
the leaf, margins spirally once or more revolute from base to 
apex; leaf cells golden yellow at the base, linear in the median 
portion I to 8 or 1 to 10, broader and shorter at the extreme 
base and short rectangular to quadrate toward the margins 
with yellowish pellucid walls, gradually shorter above, in upper 
half quadrate hexagonal, 10 to 12 win diameter, highly chlorophyl- 
lose and obscure with numerous papillae on both sides. Costa 
light brown, strong, about 90 wu wide from base to apex, smooth, 
in cross section showing two large median guide cells with one 
layer of about three somewhat smaller cells on the ventral side 
and a thick stereid band of three or more layers on the dorsal 
side with the outer row of cells somewhat larger. 
Type:—On dry shaded ledges, Bear Canyon, Santa Catalina 
Mts., Pima County, Arizona. 2500 ft. E. B. Bartram No. 307. 
January 6, 1923. 
Exsicc:—Mosses of So. Arizona No. 93. 
Frequent and abundant on dry shaded ledges in the foothills 
_ of the Santa Catalina Mts. and the Tucson Mts. The absence of 
sporophytes leaves the relative position of this species rather 
uncertain but the characters in the aggregate seem to indicate 
a relationship to Tortula muralis, from any form of which it is 
abundantly distinct in leaf outline, spirally revolute margins 
and in the yellow pellucid basal areolation without any sugges- 
tion of hyaline cells. 
