112 NORTH AMERICAN FLORA [VoLumE 15 
to below the middle of the leaf; lower leaf-cells elongate, with rather uniformly thickened, 
sometimes slightly curving walls, the alar ones mostly brownish, enlarged, scarcely forming 
auricles, 
TYPE LocaLIty: Costa Rica. 
DistTrRiIsuTion: Known only from the type locality, in mountains at 1500-2500 meters. 
5. Leucoloma Schwaneckeanum (Hampe) E. G. Britton. 
Dicranum Schwaneckeanum Hampe, Linnaea 25: 361. 1853. 
Dicranum portoricense C. Mill. Hedwigia 37: 226. 1898. 
Leucolome portoricense Paris, Index Byrol. Suppl. 233. 1900. 
Flowers and fruit unknown: plants in pale-green tufts, with often branching, erect-flexuous 
stems up to 4 cm. high: stem-leaves lanceolate-subulate, mostly falcate-secund with the 
point variously curved and twisted, up to 8 mm. long, subtubulose, on the back smooth or 
slightly papillose just below the apex, the slender point grooved and serrulate; costa pale, 
excutrent, about 30 « wide below and one eighth to one tenth the width of the lower part of 
the leaf; hyaline border extending from near the apex to the base, very narrow above, widest 
about three fourths down, becoming 10-12 cells wide, then mostly narrowing to the base; the 
very pale-green cells of the blade above from nearly square to roundish or short-oblong, about 
4 yu by 4-6 p, gradually lengthening below to mostly 6 « wide by 12~25 » long, with somewhat 
thickened walls not pitted or sinuous; alar cells brownish to hyaline, often inflated and auricu- 
late. 
TYPE LocaLIty: Porto Rico. 
DISTRIBUTION: Mountains of Porto Rico. 
6. Leucoloma Mariei Besch. Jour. de Bot. 5: 145. 1891. 
Flowers and fruit unknown: plants in dusky, somewhat reddish-green tufts with more or 
less branching stems 1—2 ecm. high: leaves somewhat curved-secund, up to 5 mm. long, lance- 
olate-subulate, subtubulose, entire except at the denticulate apex, rather densely covered on 
the back with low papillae to below the middle of the leaf except on the ill-defined border which 
is very narrow above, gradually widening below, and composed of narrower but scarcely 
paler cells than within; costa mostly somewhat excurrent, at the base about 30 « wide; cells 
of the leaf-blade all elongate, the upper mostly 3-6 times as long as wide with slightly thickened 
walls, becoming longer toward the base with thickened more or less pitted walls; alar cells form- 
ing a large, reddish-brown group aieara nearly to the costa. 
‘TYPE LOCALITY: Guadeloupe. co an 
a Known only from the — locali ity. 
7. Leucoloma tortellum (Mitt.) Jaeger, Ber. St. Gall. 
Nat. Ges. 1870-71: 413. 1872. 
Poecilophyllum tortellum Mitt. Jour. Linn. Soc. 12:94. 1869. 
Flowers and fruit unknown: plants in low mats, yellowish or dull-green at the surface, 
dusky-brown within; stems branching, 1-2 cm. high, with leaves spreading on all sides from 
the base when either wet or dry, the apex when dry crispate: stem-leaves 2.5-3 mm. long, froma 
somewhat ovate base gradually narrowed to a mostly nearly linear, grooved point, with blunt, 
slightly denticulate apex; costa nearly or quite percurrent, about 30 « wide below; leaf-surfaces 
minutely and densely papillose on both sides three fourths down the leaf or more, the margins 
above papillose, below from near the middle to the base: hyaline, with 2 or 3 rows of long, 
narrow cells; upper leaf-cells rather obscure, roundish or nearly square, about 5 by 5 yu, the 
short cells extending three fourths down the leaf or more, gradually becoming rectangular in 
the base, about 6-8 » wide by 12-25 u long, with slightly thickened walls; alar cells brownish, 
forming a large, often inflated cluster, extending nearly to the costa. 
TYPE LOCALITY: ‘Frtrrictert. 
DISTRIBUTION: Guadeloupe; alse-+n—Frinitterd. 
DOUBTFUL SPECIES 
Leucoloma Dussianum Besch.; Ren. & Card. Bull. Soc. Bot. Belg. 414: 16. 1905. No 
specimens have been seen; from the description, it seems to be much like L. subimmarginatum. 
