338 BARTRAM: TORTULA IN SOUTHERN ARIZONA 
by Dixon and Nicholson from Meran, S. Tyrol, Aug. 15, 1904. 
Apparently this is the first record from North America. 
xsicc:—Bartr. Mosses of So. Arizona No. 71 and No. 94. 
TORTULA FRAGILIFOLIA sp. nov. (PLATE 7) Evidently 
dioicous, only sterile Q plants found. Plants robust, from I 
to 1.5 cm. high, branched above, strongly rufous tinged and 
lustrous throughout in dense cushions closely matted together 
with red radicles. Leaves erect spreading when moist, folded 
lengthwise and closely spirally incurved when dry, up to 2.5 
mm. long, slightly concave, oblong spatulate to ovate oblong 
in outline, apex obtuse, shortly mucronate by the excurrent red- 
brown costa, margins narrowly recurved in the middle, distinctly 
crenately lobed in the upper half, torn and broken in various 
ways so that complete leaves are rarely if ever present; leaf 
cells rectangular and hyaline at the base, a well defined area of 
larger cells with richly colored walls in the median portion on 
either side of the costa bordered by a marginal band of about 
six rows of much smaller short rectangular cells, quickly be- 
coming shorter and hexagonal quadrate above, 10 to 12 uv in 
diameter, strongly papillose on both sides with 4 to 7 large 
C shaped or forked papillae; costa red-brown, more or less rough 
and papillose on the back, in cross section showing two large 
median guide cells, about three smaller cells in one or two layers 
on the ventral side and a thick stereid band of three or more 
layers on the dorsal side with the outer cells little or not differenti- 
ated. Reduced branches bearing ecostate, ovate acuminate, 
verrucose propagula in the form of imbricated brood leaves are 
found sparingly in the axils of the upper stem leaves. 
Type:—On bark near the base of Live Oaks along Baldy 
Trail, Santa Rita Mts., Santa Cruz County, Arizona. 7500 ft. 
E. B. Bartram No. 860. February 4, 1924. 
Exsicc:—Bartr. Mosses of So. Arizona No. -87. 
This plant suggests some connection with JT. alpina var. 
inermis bat the habitat on tree trunks, the dense cushions closely 
bound together by radicles, the very fragile structure of the 
lamina and the strongly crenately lobed margins would seem 
sufficient in the aggregate to give the plant a specific identity. 
It seems to be well distributed over the Santa Rita Mts. on bark 
near the base of oak trees above 6000 ft. but is more robust and 
characteristically developed at altitudes of 7500 ft. and over. 
