POLYPODIACEAE 17 



segments, with 6-8 veinlets on each side of the lower ones of contiguous groups : sori near 

 the ends of the veins, mainly in the segments. 

 In thickets, Florida. 



24. MATTEUCCIA Todaro. 



Stately ferns with large rootstocks. Leaves in crowns, the sterile and fertile different : 

 blades pinnate or pinnatifid : sori round, borne on the veins of a contracted fertile leaf 

 concealed by their revolute margins. Veins free. 



1 Matteuccia Struthidpteris ( L. ) Todaro. Fertile leaves 3-5 dm. long; blades simply 

 pinnate, with necklace-shaped leaflets formed of the strongly revolute margins ; sterile leaves 

 6-18 dm. long ; blades broadly lanceolate, 2-pinnatifid, the lowest leaflets gradually much 

 shorter: veins pinnate: sori crowded, confluent. [Onodea Struthiopteris (L. ) Hoffm.] 



In moist thickets, especially on river banks, Nova Scotia to British Columbia, south to New Jersey 

 and Arkansas. OSTRICH FERN. 



25. PHEGOPTERIS Fee. 



Low rather tender ferns, with horizontal rootstalks. Leaves few, the fertile and sterile 

 similar : petioles continuous with the rootstocks : blades ternate or 2-3-pinnatifid. Sori 

 round, each on the back of a vein just below its tip or on the middle of the veinlets. In- 

 dusium wanting or rudimentary. Veins free. OAK or BEECH-FERN. 



1. Phegopteris hexagondptera ( Michx. ) Fe'e. Rootstock chaffy, somewhat fleshy. 

 Petioles 2-4.5 dm. long, straw-colored, naked; leaf-blades triangular, as broad as long or 

 broader, 2-3 dm. wide, slightly pubescent and often slightly glandular beneath, acuminate ; 

 uppermost leaflets oblong, obtuse, dentate or entire, small, the middle ones lanceolate, 

 acuminate, the very large lowest pair broadest near the middle, pinnately parted nearly to 

 the midvein into linear-oblong obtuse segments : sori mostly near the maVgin. 



In dry woods, Quebec to Minnesota, south to Florida and Louisiana. 



26. GONIOPTERIS Presl. 



Rather large ferns of woods and rocky places, with horizontal rootstocks. Leaves pin- 

 natifid or bipinnatifid. Sori on the back of the veins normally without an indusium. 

 Veins connivent, the branches form contiguous groups uniting to form one or more arches. 



Sporiferous leaves of two sorts, one rigid, pinnatifid toward the apex, the other lax, pinnate through- 

 out, and proliferous. 1. O. rcptans. 

 Sporiferous leaves of one sort, with large terminal leaflets. 2. G. tetragona. 



1. Goniopteris r6ptans (Sw. ) Presl. Leaves spreading or procumbent ; petioles 7-25 

 cm. long, clustered, grayish straw-colored, slender, naked ; blades 10-30 cm. long, mem- 

 branous, softly pubescent with branched or stellate hairs, oblong-lanceolate, pinnate, with 

 nearly or quite sessile crenately pinnatifid leaflets, the apex merely pinnatifid, often elon- 

 gated and rooting : veins pinnate, simple, the basal veinlets often anastomosing : sori on 

 the middle of the veinlets, sometimes with a rudimentary indusium. 



On calcareous rocks, middle and peninsular Florida. Also in the West Indies. 



2. Goniopteris tetragona (Sw. ) Presl. Leaves erect; petioles 15-45 cm. long, 

 sometimes slightly villous ; blades 3-6 dm. long, 15-30 cm. wide ; leaflets numerous, 

 spreading, 7.5-15 cm. long, the lowest narrowed at the base and sometimes stalked, deeply 

 pinnatifid, thin-herbaceous, the lower surface and the rachis finely pubescent : sori in rows 

 near the midrib. 



In rocky woods, Marion County, Florida. Also in tropical America. 



27. NEPHROLEPIS Schott. 



More or less epiphytic plants. Leaves spreading or pendent : blades elongated : leaf- 

 lets numerous, approximate, jointed at the base, with whitish dots on the upper surface. 

 Sori round, rising from the apex of the upper branch of a vein, usually near the margin. 

 Veins free. 



Leaf-blades 7-15 cm. wide : indusia distinctly reniform. 1. N. exaltata. 



Leaf-blades 20-30 cm. wide : indusia nearly orbicular. 2. N. biserrata. 



1. Nepbrolepis exaltata (L.) Schott. Petioles 10-15 cm. long ; leaf-blades various, 

 3-20 dm. long, 7-15 cm. wide ; leaflets lanceolate, sometimes crenulate, the upper side 

 auricled at the base, the lower rounded ; the rachis nearly naked : sori almost marginal, 

 covered with firm distinctly reniform indusia. 



On logs and stumps, peninsular Florida. Also in the tropics. SWORD OR BOSTON FERN. 



2. Nephrolepis biserrata (Sw. ) Schott. Petioles 10-20 cm. long; leaf -blades 6-12, 

 dm. long, 20-40 cm. wide ; leaflets 10-20 cm. long, acute, entire or crenulate, the upper 



2 



