FERN FAMILY 



branous. hoodlikc, attached at the inner side of the broad base and partly under the sorus, 



early thrust back by the sporangia and partly concealed, withering, the sori thus appearing 



naked with age. 



About ten species, chiefly of temperate and boreal regions. Two besides F. fragilis occur in North 

 America. Type species, Polypodinin biilbifcnim L. 



1. Filix fragilis ( L. ) Gilib. I'.rittle-fern. Fig. 12. 



Polypodium fragile L. Sp. PI. 1091. 1753. 

 FilLv fragilis Gilib. E.xerc. Phyt. 558. 1792. 

 Cvstoftcris fragilis Bernh. Schrad. Neues Tourn. 

 1806. 



Bot. 1-: 27. pi. 2, f. 9. 



Rhizome creeping, paleaceous toward the apex, the scales thin, 

 ovate, acuminate. Fronds few or seyeral, erect-spreading, usually 

 clustered ; stipes about as long as the blades, stramineous to light 

 castaneous, delicate, fragile ; blades extremely variable, mostly 

 oblong-lanceolate to lance-ovate, acuminate, about 10-25 cm. 

 long, nearly or quite 2-pinnate ; pinnae deltoid to deltoid-oblong 

 or oblong-ovate, acutish to acuminate, glabrous ; pinnules few or 

 many, spreading, mostly ovate or oblong-lanceolate, pinnatifid 

 or incised, acutish, mostly decurrent and joined, membranous; 

 veinlets mostly excurrent to marginal teeth ; sori small ; indusia 

 roundish or ovate-acuminate, deeply convex, tlie apex often 

 toothed. 



Rocky woods and low moist situations, Humid Transition to Arctic 

 Zones: Alaska to Labrador and Newfoundland, south to southern Califor- 

 nia, the Mexican Border region, Oklahoma, Alabama and Georgia; also in 

 Eurasia and tropical America. Polymorphic. Type locality, European. 



3. POLYPODIUM [Tourn. 1 L. Sp. PI. 1082. 1753. 



Mostly shade-loving species, of various habitat, commonly epiphytic, the rhizomes 

 usually slender and creeping, often widely so. Fronds uniform or sul^dimorphous, usually 

 articulate to knob-like prominences of the rhizome; blades simple. 1-3-pinnate, or variously 

 pinnatifid. glabrous, pubescent, or paleaceous ; venation free or variously areolate. Sori 

 round to elliptical, relatively large, dorsal or sometimes terminal, invariably non-indusiate. 

 [Name Greek, meaning many feet, alluding to the numerous knoblike prominences of the 

 rhizome.] 



Several hundred species, mainly of tropical and subtropical regions. A few additional species occur in 

 other parts of the United States. Type species, Polypodium i-ulgare L. 



Segments rigidly coriaceous, the midribs scaly at first; sori very large, crowded against the midrib. 



1. P. scout eri. 

 Segments membranous to herbaceous, not scaly; sori smaller, apart from the midrib. 



Blades mostly less than 15 cm. long; segments oblong to elliptical; sori medial, few. 2. P. hesperium. 

 Blades mostly 15 to 50 cm. long; segments linear; sori inframedial, numerous. 



Blades usually lanceolate; segments linear-attenuate, mostly dilatate; veins free, oblique-spreading, 



mostly translucent. 3. P. glycyrrlnsa. 



Blades oblong to deltoid or deltoid-ovate; segments oblong-linear, mostly decurrent; veins casually 

 or regularly areolate, oblique, mostly opaque. 4. P. calitornicum. 



1. Polypodium scoiileri Hook. & Grev. 

 Coast Polypody. Fig. 13. 



Polypodium sconleri Hook. & Grev. Icon. Fil. 1: pi. 56. 1829. 

 Polypodium pachvphvllum D. C. Eaton, Am. Journ. Sci. II. 22: 



138. 1856. 

 Polypodium car)iosum Kell. Proc. Calif. Acad. 2: 88. /. 24. 



1861. , 



Rhizome creeping, woody, 6-10 mm. thick, laxly 

 paleaceous, naked with age, whitish-pruinose ; scales 

 dark castaneous. attenuate from a deltoid-ovate base, 

 about 1 cm. long, denticulate. Fronds few, mostly 

 15-70 cm. long; stipes stout, rigid, shorter than the 

 blade, naked; blades deltoid-ovate, mostly 10-40 cm. 

 long, pinnatisect ; segments 2-14 pairs, linear to linear- 

 oblong, obtuse. 7-20 mm. broad, spreading, adnate. 

 slightly decurrent. very rigidly coriaceous, the carti- 

 laginous border crenate to obscurely crenulate-serrate ; 

 midribs elevated, deciduously scaly beneath ; vein^ 

 joined in a single series of areoles ; sori very large, 

 crowded against the midrib, mostly confined to the 

 upper segments. 



On mossy tree-trunks, cliffs, and rock-slopes. Humid Transi- 

 tion Zone; along the coast from Santa Cruz County, California, 

 to Vancouver Island; also on Guadalupe Island, Lower Califor- 

 nia. Type locality: Columbia River region. 



