POLYPODIACEAE 9 
Leaf-blades ovate-lanceolate or deltoid in outline, pinnately compound. 
Leaf-blades 1-2-pinnate: leaflets persistent. 1. A. Capillus- Veneris. 
Leaf-blades 3-4-pinnate : leaflets deciduous. 2. A. tenerum. 
Leaf-blades roundish or reniform, dichotomously forked, with pinnate branches. 3. A. pedatum. 
1. Adiantum Capíllus-Véneris L.  Rootstocks creeping, slender, chaffy with light 
brown scales. Leaves numerous ; petioles very slender, black or nearly so, shining, 7-22 
cm. long; blades ovate-lanceolate in outline, 2-pinnate below, l-pinnate above, mem- 
branous, commonly drooping, 1.5-5 dm. long, 1-3 dm. wide at the base ; leaflets cuneate- 
obovate or rhomboid, rather long-stalked, glabrous, the upper margin incised, crenate or 
dentate-serrate except where it forms the indusia. 
In ravines, preferring limestone, Virginia to Missouri, South Dakota and California, south to 
Florida and Louisiana. Rareorlocal. Alsoin warm-temperate regions generally. 
2. Adiantum ténerum Sw. Leaves several; petioles 3 dm. tall, glossy ; blades del- 
toid, 3-9 dm. long, 2-4 dm. wide, 3-4-pinnate ; leaflets articulated at the base, and falling 
away at maturity, cuneate, the upper edge sometimes angular, broadly and often deeply 
lobed : sori numerous, roundish or transversely oblong. 
In sink-holes in lime-rock, central peninsular Florida. Also in tropical America. 
3. Adiantum pedàtum L. Rootstocks slender, chaffy. Leaves numerous ; petioles 
2-4.5 dm. long, dark chestnut-brown, polished and shining, dichotomously and pedately 
forked ; blades nearly orbicular or reniform in outline, 2-4.5 cm. broad, the larger divi- 
sions 1.5-2.5 dm. long: leaflets oblong, triangular-oblong or the terminal one fan-shaped, 
all short-stalked, the upper margin toothed, cleft or lobed, bearing the linear-oblong sori. 
. In woods, Nova Scotia to British Columbia and Alaska, south to Georgia, Mississippi and Califor- 
nia. Also said to occur in western Asia. MAIDENHAIR FERN. 
11. PELLABA Link. 
Rock-inhabiting plants, relatively small in size, with pinnate or pinnatifid leaf-blades. 
Sterile and fertile leaves similar: petioles usually dark colored. Sori intramarginal, borne 
on the ends of unconnected veins, at length confluent and forming marginal lines. In- 
dusium commonly broad, membranous, formed of the reflexed margins of fertile leaflets 
more or less modified, and membranous. CLIFF-BRAKE. 
Indusium broad : leaflets often narrow. 
Leaf-blades 1-2-pinnate. 
Leaflets obtuse or barely acute. 
Petioles and leaflets smooth. 1. P. atropurpurea. 
Petioles and leaflets scurfy-pubescent. 2. P. aspera. 
Leaflets mucronate or decidedly acute. 3. P. Wrightiana. . 
Leaf-blades 3-4-pinnate: leaflets numerous, 4. P. pulchella. 
Indusium very narrow: leaflets broad: rachis zigzag. 5. P. flexuosa. 
1. Pellaea atropurpürea (L.) Link. Rootstocks short, densely clothed with rusty 
hair-like scales. Leaves tufted ; petioles 5-15 cm. long, dark purple or nearly black ; 
blades leathery, lanceolate or ovate-lanceolate in outline, 1-3 dm. long, simply pinnate or 
2-pinnate below ; rachis dark-brown or purple; leaflets 2.5-5 cm. long, glabrous, some- 
times sessile: veins obscure, commonly twice forked, 
On rocks, preferring limestone, Ontario to British Columbia, Massachusetts, New Jersey, Georgia 
and Arizona. 
2. Pellaea áspera (Hook.) Baker. Leaves several; petioles slender, 5-8 cm. long, 
with scurfy pubescence ; blades oblong-lanceolate, 10-15 cm. long, 2-pinnate ; leaflets del- 
toid-lanceolate or oblong, those next to the main rachis often lobed, all scabrous on both 
surfaces. 
On dry rocks, Texas and New Mexico. 
3. Pellaea Wrightiàna Hook. Rootstocks stout, densely chaffy. Petioles crowded, 
purplish brown, 10-15 cm. long ; leaf-blades lanceolate to deltoid, 10-25 cm. long, 2-pinnate, 
or 3-foliolate at the apex ; leaflets mucronulate, the ultimate ones often long and narrow ; 
spore-bearing ones with margins inflexed to the midrib. 
On rocks, Colorado to Texas and California. Also in Mexico. 
4. Pellaea pulchélla ( Mart. & Gal.) Fée. Leaves clustered ; petioles 7-15 cm. long, 
chaffy at the base, nearly black ; blades 7-18 em. long, triangular ovate, 4-pinnate below, 
gradually simpler above ; leaflets numerous, oval or cordate-ovate, 2-6 mm. long, stalked, 
ieathery, smooth. 
In dry places, western Texas and New Mexico. Also from Mexico to Chile. 
5. Pellaea flexuósa (Kaulf.) Link.  Rootstocks slender. Leaves several; petioles 
reddish, passing into the zigzag rachis, with deflected and zigzag nearly smooth secondary 
