136  LEJEUNEAE OF THE UNITED STATES AND CANADA 
Lejeunea (Euosmo-Lejeunea) duriuscula Steph. Hedwigia, 29: 
80. 1890. 
Lejeunea (Eu-Lejeunea) Underwoodii Steph. Bot. Gazette, 17: 
17 h 4802, 
Cheilolejeunea duriuscula Schiffn.; Englers Bot. Jahrb. 23: 
592. 1897 (in obs.). 
Yellowish-green, sometimes tinged with brownish, depressed- 
caespitose : stems prostrate, loosely appressed to substratum, 
0.08 mm. in diameter, sparingly and irregularly branched : rhizoids 
scanty : leaves slightly imbricated, the lobe convex, obliquely to 
widely spreading, falcate-ovate, 0.4 mm. long, 0.35 mm. wide, 
rounded or very obtuse at the apex, margin slightly and irregu- 
larly angular-sinuate, antical margin arching across or just beyond 
axis, rounded at base, postical margin forming an obtuse angle 
with keel; lobule strongly inflated, triangular-ovate, measuring 
when inflated 0.1 mm. long, 0.08 mm. wide, keel slightly arched 
or almost straight, somewhat decurrent, free margin strongly in- 
volute to beyond the obtusely pointed or apiculate apex, then 
obliquely truncate to end of keel ; cells of lobe plane or slightly 
convex, with somewhat thickened walls and large, triangular 
trigones, averaging 13 ۸ in diameter at edge of lobe, 16 م‎ in the 
middle and 21 y at base: underleaves distant, ovate to orbicular, 
0.17 mm. long, 0.15 mm. wide, bifid about one half with acute, 
slightly spreading lobes and narrow usually acute sinus, cuneate 
and slightly decurrent at base, sometimes very minutely auricu- 
late : inflorescence dioicous: 9 inflorescence borne on a leading 
branch, innovating on one or sometimes on both sides, the inno- 
vations long, often floriferous ; bracts complicate, unequally bifid, 
the lobe suberect to widely spreading, ovate to falcate-ovate, 
rounded to obtuse at the apex, margin as in leaves, 0.5 mm. long, 
0.3 mm. wide, lobule ovate to lanceolate, rounded to acuminate 
at the apex, 0.17 
, 
pairs, very concave and strongly inflated, shortly and subequally 
bifid with a strongly arched keel and rounded or obtuse lobes, 
slightly crenulate at apex ; bracteoles similar to underleaves but 
smaller, present only in lower part of spike. 
