New ferns from tropical America—lll 
MARGARET SLOSSON 
(WITH PLATE 26) 
Trichomanes rhipidophyllum Slosson, sp. nov. 
Rhizome creeping, about 5 mm. in diameter, thickly tomentose; 
stipes brown and tomentose to within about 1 mm. of the lamina, 
then green, slightly hairy, and winged by the narrowly and 
abruptly decurrent base of the lamina, in fertile fronds 5-7 mm. 
long, in sterile 1.5-3 mm. long; laminae shining bright green, 
delicately papyraceous, the fertile 0.8-1.1 cm. long, 0.7-1.3 cm. 
broad, suborbicular, almost semicircular, or subtrapezoid, at 
apex slightly once cleft, at base subtruncate or cuneate, the sterile 
0.4-1.3 cm. long, 0.5-1.5 cm. broad, round-reniform to ovate or 
broadly obovate; margins irregularly undulate or sublobate, 
marginal hairs few, slender, simple or 
binate; surfaces or at least the lower one 
with a few short club-shaped mostly 
2-celled hairs on the veins; veins few, 
distant, in the sterile fronds subflabel- 
lately forked, midveins of fertile fronds 
flexuose, with about 3 pairs of branches 
forked 1-4 times, spurious veins short, 
almost none; cells of the lamina between 
the veins variable, mostly narrow, 0.056- 
0.116 mm. long, 0.020-0.040 mm. broad, 
their walls 0.004-0.008 mm. broad; in- 
volucres 1-2, borne at the base of the 
central cleft of the lamina, almost wholly = Trichomanes rhipidophyllum. 
exserted, the lips 1.5 mm. broad, their 1, cellular structure of the mar- 
- brown border 1-4 cells deep; spores glo- gin of the lip of the involucre, 
, 0.044—-0.056 mm. in diameter. nlarged; - cells ep between 
Type in the Underwood Herbarium rather eb aapal dowd dak! 
at the New York Botanical Garden, 
collected on a tree in a damp forest near Onaca, Colombia, at 
an altitude of 760 m., Aug. 24, 1898-99, Herbert H. Smith 2445. 
A note on the label says ‘not observed elsewhere.” <A very 
en 
§ OU Ul > a é 
687 
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