76 NORTH AMERICAN FLORA [VoLUME 16 
to the costa; indusium globose, pale, membranous, bursting irregularly, quickly fragmen- 
tary or disappearing ; receptacle elevated, subglobose, dark, deciduously grayish furfuraceo- 
pilose. 
TYPE LOCALITY: Navarro La Luna, Costa Rica: 
DISTRIBUTION: Known only from Costa Rica. 
18. Cyathea hastulata Christ, Bull. Herb. Boiss. II. 4: 945. 1904. 
Caudex and stipe undescribed; frond very ample, tripinnate; primary rachis stout, 
unarmed, purplish-castaneous, lustrous beneath a very short detergible rufous pubescence, 
the secondary rachises similar; pinnae subsessile to petiolate (2.5 cm.), narrowly oblong, 
about 70 em. long, 22 cm. broad, very abruptly acuminate, the apex pinnate; pinnules 
about 30 pairs, dark-green above, rather lighter below, rigidly herbaceous, approximate, 
spreading, sessile, narrowly oblong, 11-13 cm. long, up to 2.5 em. broad, acuminate or 
long-acuminate, the costae slender, very narrowly sinuate-alate, brownish, with a few 
lacerate grayish squamules; segments 20-23 pairs, distant, falcate, linear-oblong, 12-14 
mm. long, about 3 mm, broad, sessile or at least constricted at the base, deeply crenate- 
dentate, the teeth obtuse, more than 1 mm. each way, the lowermost outer one usually 
produced to 2-3 mm. in length, the segment thus unequally hastulate ; veins of the lower 
lobes pinnately forked, 2 or 3 pairs, in the upper lobes once-forked near the costule, both 
the costules and the basal portions of the veins grayish-squamulose; sori about 9 pairs, 
small, brownish, close to the costule, extending nearly to the apex; indusium globose, 
pale yellowish-brown, fragile, readily rupturing, the basal portion subpersistent, disciform ; 
receptacle dark, elevated, globose-capitate, deciduously grayish squamulose-pubescent. 
TYPE LOCALITY: Arias Agua Punta, Costa Rica. 
DISTRIBUTION: Known only from Costa Rica. 
19. Cyathea Tuerckheimii Maxon, Contr. U. S. Nat. 
Herb. 13: 4. 1909. 
Trunk and stipe wanting; fronds ample, at least 130 cm. broad, very deeply tripinnati- 
fid; primary rachis yellowish-brown below, very densely furfuraceous with minute deciduous 
yellowish-brown scales and armed with numerous short (1-1.5 mm.) straight erect spines, 
tuberculate and glabrate with age; pinnae 65 cm. long, 25 cm. broad, petiolate (1.5-2.5 
cm.), lanceolate, acuminate, the secondary rachis spinescent, clothed like the primary 
rachis ; pinnules 11 or 12 cm. long, 1.7-2 em. broad above the base, about 28-30 pairs below 
the deeply serrate apex, mostly short-petiolate (the lower ones 4 or 5 mm.), contiguous, 
narrowly lanceolate, attenuate, mostly at right angles, cut nearly to the costa, the costae 
yellowish-brown with a few minute short hairs and numerous very caducous glossy dark- 
brown ovate-lanceolate attenuate erose scales about 2 mm. long; segments about 20-22 
pairs, rigidly coriaceous, narrow, 10-12 mm. long, 3-3.5 mm. broad, falcate, the basal ones 
separate, the others somewhat dilatate and connected by a narrow wing, the margins sim- 
ply crenate-serrate, revolute in drying, especially toward the subacute apex, the costules 
clothed similarly to the costae, but the scales lighter in color (yellowish-brown), triangular- 
ovate, long-acuminate, somewhat bullate, with a few stout curved septate whitish hairs 
intermixed; veins of the segments 10 or 11 pairs, forked near the base, elevated, glabrate ; 
sori large, yellowish, 6-9 pairs, occupying two thirds or more of the segment, seated at the 
forking of the veins; indusia membranous, rupturing irregularly, subpersistent; receptacles 
large, conspicuously hirsute. 
TYPE LOCALITY: Near Coban, Alta Verapaz, Guatemala, altitude about 1350 meters. 
DISTRIBUTION: Alta Verapaz, Guatemala, at from 1350 to 2000 meters elevation; region of 
Orizaba, Vera Cruz, Mexico, altitude about 1300 meters. 
20. Cyathea gracilis Griseb. Fl. Brit. W. Ind. 704. 1864. 
Caudex erect or decumbent, occasionally attaining a height of 3 meters, 5-7 cm. in 
diameter, clothed with the closely placed appressed dark-castaneous persistent stipe-bases 
of previous seasons; fronds 1.5-2.25 meters long, of lax habit, the leafy parts relatively 
very broad, spaced, and petiolate; stipe erect, spreading, 60-75 cm. long, light-castaneous, 
