MAXON—STUDIES OF TROPICAL AMERICAN FERNS. 179 
following single new species, make a total of forty-nine to be recog- 
nized from North America.’ 
Cyathea asperula Maxon, sp. nov. 
Caudex, stipes, and shape of lamina unknown; lamina presumably about 2 meters 
long, 70 cm. broad, deeply tripinnatifid, the primary rachis slender (about 4 mm. 
thick), olivaceous, minutely and deciduously furfuraceous, sparingly beset with small 
slender straight spines about 0.5 to 1 mm. long; pinne subopposite, sessile, oblong, 
abruptly acuminate, 30 to 35 cm. long, 11 to 14cm. broad, the secondary rachis slender, 
yellowish brown, strigose above, below scabrous or asperulous only toward the base, 
the spines very minute; pinnules about 18 pairs, narrowly oblong, long-acuminate to 
subcaudate, 5 to 7 cm. long, 15 to 18 mm. broad, contiguous or nearly so, subsessile, 
spreading, cut nearly to the costa at the base, less deeply outward, the costal wing 
about 1 mm. broad upon each side toward the apex, the costa slender, laxly strigose 
above, below bearing numerous minute strongly bullate roundish bright brown scales 
(with slender long-pointed tips) and toward the base a few linear scales (1 to 1.5 mm. 
long) with minutely fimbriate margins, the teeth mostly gland-tipped; segments 12 
to 14 pairs, slightly falcate, obtuse, 8 to 10 mm. long, 3.5 to4 mm. broad, the basal pair 
constricted and apart, coarsely incised and commonly semihastulate upon the proxi- 
mal margin, the others not constricted, slightly dilatate, separated by narrow linear 
sinuses, the margins lightly serrate-crenate; costules slender, bearing 3 or 4 spine-like 
hairs above, below bearing numerous minute bullate scales (like those of the costa) 
and a few distant curved hairs; veins 6 to 8 pairs, oblique, mostly once forked; sori 
nearly medial; indusium globose, yellowish brown, delicately membranous, rup- 
turing irregularly, the divisions subpersistent on all sides; receptacle capitate, con- 
spicuously setiferous. 
Type in the U. S. National Herbarium, no. 690466, collected in forests near Con- 
stanza, Santo Domingo, altitude 1,250 meters, March, 1910, by H. von Tirckheim 
(no. 3056); distributed as Cyathea muricata Willd. 
Cyathea asperula is an exceedingly well marked species. From Cyathea tenera 
(J. Smith) Griseb., which has similarly muricate or minutely spiny rachises, it differs 
in its copious covering of bullate scales upon the costa and costules, and in being 
nearly devoid of hairs below (instead of strongly pubescent upon the coste, costules, 
and veins), as well as in its fewer pinnules, fewer and differently shaped segments, 
and in other obvious characters. 
1See N. Amer. Fl. 16: 65-88. 1909. 
