1042 POLYPODIACEAE 



or triangular-ovate, pinnately parted or pinnate below; segments oblong, obtuse, 

 crenate-dentate or the lower pinnatifid with toothed lobes. "N.S." — N.H. — Ga. 

 — N.M.— Wis.; Ariz, and (?) "B.C." 



4. FILIX Adans. 



Ferns, with pinnately compound fronds of rather thin texture. Sori roundish, 

 indusiate, borne on the veins. Indusia delicate, hood-like or flattish, attached 

 at one side of and partly under the sorus, at first arched over it, finally thrown 

 back or withering. Veins free. [Cystopteris Bernh.] 



Blades of the fronds deltoid-lanceolate or broadly lanceolate, twice or thrice pinnate. 

 Blades elongate deltoid-lanceolate, 3-12 dm. long; basal pair of pinnae the largest. 



1. F. bulbifera. 

 Blades broadly lanceolate, 2-4.5 dm. long; basal pair of pinnae usually slightly short- 

 ened. . 2. F. frag, is. 

 Blades of the fronds deltoid-ovate, three to four times pinnate. 3. F. monlana. 



1. F. bulbifera (L.) Underw. Rhizome short; fronds clustered; blades 

 minutely more or less glandular beneath, especially on the rachises and midribs; 

 pinnae oblong-ovate to lanceolate-oblong, pinnate; pinnules unequally oblong- 

 ovate, obtuse, variously incised to deeply pinnatifid, more or less adnate or free ; 

 rpchis and pinnae commonly bulbiferous beneath, the bulblets producing new 

 plants after falling to the ground; indusia short, convex, truncate. C. bulbifera 

 (L.) Bernh. Damp places, especially about rocks: "Ne\vf."— N.S.— "Man."— 

 Wis. — Ark.— Ga.; Utah— Ariz. Boreal— Austr.— Son. 



2. F. fragilis (L.) Gilib. Rhizome creeping; fronds clustered or shghtly 

 scattered, glabrous; stipe and primary rachis slender, brittle, stramineous or 

 brownish below; secondary rachises usually winged; pinnae deltoid-lanceolate or 

 deltoid-ovate; segments deciu-rent, variable, roundish-oval or ovate or rhomboid- 

 ovate or ovate-lanceolate, dentate, with short obtuse teeth or deeply toothed or 

 cleft, with narrower teeth, or cleft or sometimes pinnatifid, with toothed segments; 

 indusia delicate, convex, roimdish or commonly pointed, often toothed or lacini- 

 ate at apex. Cijstopteris fragilis (L.) Bernh. Rocky places: Greenl.— Ga.— 

 Okla.— Calif.— Alaska; trop. Am., and the Old World. Plain— Alp. 



3. F. montana (Lam.) Underw. Rhizome slender, creeping; fronds scat- 

 tered, 12-45 cm. long; stipes slender; blades often subternate; basal pair of pin- 

 nae much the largest, unequally deltoid-ovate; pinnules deeply divided; segments 

 oblong, deeply toothed or divided; indusia convex, ovate, soon thrown back or 

 evanescent. Lab.— Que.— Ont.; Colo.; B.C.— Alaska; Eurasia. Mont.— Sub- 

 alp. 



5. POLYSTICHUM Roth. Holly Fern, Christmas Fern. 



Ferns of mostly rigid habit, with firm-textured pinnate to pinnately decom- 

 pound fronds usually with sharply toothed or spinulose margins. Son round, 

 indusiate, borne on the veins. Indusium peltate. Veins free. 

 Blades normally simply pinnate; pinnae auricled or the upper side at base, obliquely 

 trimcate at the lower. ^. , ^ • . 



Fronds very short-staUt ed ; pinnae broadly lanceolate, falcate, on the lower triangular. 



•' 1. P. lonchitis. 



Fronds rarely very short-stalked; pinnae horizontal, slightly falcate, lanceolate or 

 hnear, acuminate. 2. P. mumium. 



Blades normally more compound. . An,lpr'ir,r>i 



Blades proliferous below the apex. 3. i". Anaersoni. 



'^Pinnae serratrin^the distal part, pinnately lobod at base. 4. P scopulinurn. 



Pinnae pinnately divided almost throughout the blade, commonly fully bipinnate. 



1. p. Lonchitis (L.) Roth. Fronds growing in a crown, 8-22 cm. long; 

 stipes and rachises chaffy with light brown scales; blades linear-lanceolate, 

 gradually tapering toward "base; pinnae 1-4.5 cm. long, densely spinulose-toothed, 

 the teeth mostly spreading; sori medial or supramedial. Woods: Greenl. — N.b. — 

 " Wis." — Alta. — Colo.— Calif . — Alaska. Boreal. 



2. P. munitum (Kaulf.) Presl. Fronds growing in a crown, 22-152 cm. long; 

 stipes densely chaffy at base, less so above; rachises chaffy; scales bright reddish 



