—4i— 
Rhacomitrium FLETTII. 
Plate V. Fig. i. Plants showing mode of branching and disposition of leaves 
when moist. Natural size about 1.5 cm. X 3- Fig, 2. Leaves X 10. 
Figs. 3, 4, 5. Cross sections of a leaf from near base, middle and apex, 
respectively. Figs. 6, 7, 8. Leaf areolation from near base, middle and 
apex, respectively. 
RHACOMITRIUM FLETTII n. sp. 
John M. Holzinger. 
Stem densely caespitose, radiculose at base, simple or fasciculately 
branched; color of plants yellowish brown. Leaves divergent, then ascend- 
ing when moist, lanceolate, margin entire: costa reaching apex; cells at base 
pellucid, thin-walled, approximately rectangular, about 1x2, above more iso- 
diametric, thick-walled, with a row of more pellucid, smaller, roundish cells 
along the margin and this bistratose toward the apex. Entirely sterile. 
This plant was collected by Prof. J. B. Flett on Mt. Tacoma (Mt. Rai- 
nier), at an altitude of 14,519 feet, near one of the steam jets issuing from a 
fissure in the side of the rim of the crater, Aug. 10, 1897. 
In appearance, color and branching it looks like a diminutive form of 
Rhacomitrium ellipticum , section Dryptodon. But it has almost completely 
lost the very unequal thickenings of the cell walls above the base, has nar- 
rower leaves lacking the foldings in that species, has a heavier costa, and 
has a tendency to a doubling of the small marginal cells, as is shown in Fig. 
5 of the accompanying plate. Winona, Minn. 
