12 POLYPODIACEAE. 
a DICKSONIA L/Her. Sertum Angi. 30. 1788. 
Large ferns with 2-3-pinuatifid leaves, and creeping or erect rootstocks, many tropical 
species arborescent. Sori small, globular, marginal or submarginal. Sporanges borne in 
an elevated globular receptacle, enclosed in the membranous cup-shaped inferior indusium 
which is open at the top and on the outer side adherent toa reflexed toothlet of the leaf. 
Sporanges pedicelled, provided with a vertical ring which bursts transversely. Veins always 
free. [Name in honor of James Dickson, English nurseryman and botanist, 1738-1822.] 
About 50 species, of wide distribution, the greater number in tropical America and Polynesia. 
1. Dicksonia punctilobula (Michx.) A. Gray. Hay-scented Fern. (Fig. 22.) 
Nephrodium punctilobulum Michx. Fl. Bor. Am. 2: 
268. 1803. 
Dicksonia pilostuscula Willd. Enum. 1076. 1809. 
Dicksonta punctilobula A. Gray, Man. 628. 1848. 
Rootstock slender, extensively creeping, not 
chaffy. Stipes stout, chaffless, pale green and 
sweet-scented ; leaves 1°-3° long, 5’-9/ wide, ovate- 
lanceolate, acute or acuminate, frequently long- 
attenuate, usually 3-pinnatifid, thin and delicate; 
rachis and under surface minutely glandular and 
pubescent; sori minute, each on a recurved tooth- 
let, usually one at the upper margin of each lobe; 
sporanges few; indusium cup-shaped with a delicate 
membranous irregular margin. 
In various situations, most abundant on open hill- 
sides, New Brunswick and Ontario to Indiana and Min- 
nesota (according to Upham), south to Alabama and 
Tennessee. Ascends to 5600 ft. in Virginia. Aug. 
4. CYSTOPTERIS Bernh. Schrad. Neues Journ. Bot. 1: Part 2, 26. 1806. 
Delicate rock ferns with slender stipes, 2-4-pinnate leaves, and roundish sori borne on 
the backs of the veins. Indusium membranous, hood-like, attached by a broad base on 
its inner side and partly under the sorus, early opening and somewhat evanescent. Veins 
free. Sporanges pedicelled, provided with a transversely bursting vertical ring. [Greck, 
signifying Bladder-fern, in allusion to the inflated indusium. ] 
Five species, natives of the north temperate zone. Only the following known in North America. 
Leaves ovate-lanceolate or lanceolate, 2-3-pinnate. 
Leaves broadest at base, long-tapering, bearing bulblets beneath. 1. C. bulbifera. 
Leaves scarcely broader at base, short-pointed; no bulblets. 2. C. fragilis. 
Leaves deltoid-ovate, 3-4-pinnate. 3. C. montana, 
1. Cystopteris bulbifera (L.) Bernh. 
Bulblet Cystopteris. (Fig. 23. ) 
Polypodium bulbiferum 1. Sp. Pl. togt. 1753. 
Cystopteris bulbifera Bernh. Schrad. Neues Journ. 
Bot. 1: Part 2, 26. 1806. 
Rootstock short, copiously rooting. Stipes 4/-6’ 
long, light colored; leaves elongated, lanceolate 
from a broad base, 1°-2'3° long, 2-3-pinnatifid or 
pinnate ; pinnules crowded, toothed or pinnatifid ; 
rachis wingless, commonly bearing underneath in 
the axils of the pinnae and segments, large fleshy 
bulblets which fall away and propagate the plant; 
indusia short, truncate on the free side, early 
thrown back and withering so that the sori appear 
naked at maturity. 
On wet rocks and in ravines, especially on limestone, 
Quebec to Wisconsin, south to Tennessee and Arkansas. 
Ascends to 3500 ft. in Virginia. Ju'y-Aug. 
