POLYPODIACEAE 



7. CHEILOGRAMMA Blume. 



Epiphytes, relatively small, with simple leaf-blades. Sori linear, but the lines some- 

 times interrupted, nearly marginal. Veins reticulated. 



1. Cheilogramma lanceolatum ( L. ) Blume. Eootstocks creeping. Leaves numer- 

 ous ; petioles 2.5-5 cm. long ; blades simple, 15-32 cm. long, 12-] 6 mm. wide, entire, often 

 somewhat crisped, tapering both ways, with prominent midrib and obscure immersed 

 veins ; veins anastomosing, the outer ones free and enlarged at their apices : sori antemar- 

 ginal in a mostly continuous line near the apex. [Taenitis hnceolata (L.) K. Br.] 



On trees, Old Rhodes Key, Florida. Also in tropical America. 



8. PTERIS L. 



Relatively large plants, with petioles continuous with the rootstock and variously di- 

 vided leaf-blades. Sori marginal, linear, continuous, occupying a slender or filiform re- 

 ceptacle, connecting the tips of the free veins. Indusium membranous, single, formed from 

 the reflexed margin of the leaf-blade. Veins free. 



Lower divisions of the leaf-blades undivided. 1. P. longifolia. 



Lower divisions of the leaf-blades forked or pinnate. 



Leaflets 7-10 mm. wide, the upper scarcely decurrent. 2. P. Cretica. 



Leaflets 5 mm. wide or less, the upper strongly decurrent. ^ 3. P. serrulata. 



1. Fteris longifolia L. Leaves somewhat spreading ; petioles 15-30 cm. long, clothed 

 below with pale brown scales ; blades oblong-lanceolate, 3-6 dm. long ; leaflets linear, 4-10 

 mm. wide, entire, sessile : veins close, usually once branched : indusium yellowish brown. 



Peninsular Florida and the Keys, and Louisiana. Also widely distributed in the tropics. 



2. Pteris Cretica L. Leaves several ; petioles 15-30 cm. tall, straw-colored or pale 

 brown ; blades 15-30 cm. long ; leaflets usually 2-6 opposite pairs, sessile, the sterile con- 

 siderably broader and spinulose-serrulate, the lower pairs often parted nearly to the base 

 into 2 or 3 linear segments : indusium pale : veins free, parallel, simple or once forked. 



Peninsular Florida and the Keys. Also in tropical regions generally. 



3. Pteris serrulata L. f. Leaves several ; petioles 15-22 cm. long, naked, pale or 

 brownish ; blades ovate, 20-45 cm. long, 2-pinnatifid, the rachis with a wing 2-4 mm. wide 

 at the top, thence narrowed downward ; leaflets in 6 or more distinct opposite pairs, the 

 upper simple, the lower with several elongated linear segments on each side ; the sterile 

 portions spinulose-serrate. 



On old walls, South Carolina to Louisiana, doubtless escaped from cultivation. A native of China. 



9. FTERIDIUM Scop. 



Coarse plants growing in open sunny places, with ternately compound leaf -blades. Sori 

 marginal, linear, continuous, rising from a vein-like receptacle connecting the ends of free 

 veins. Indusium double, an outer formed by the reflexed margin of the leaf-blade and a 

 second, more delicate with the vein-like receptacle. 



Ultimate segments of the leaf-blades approximate at the base. 1. P. aquilimim. 



Ultimate segments of the leaf-blades, 4-6 mm. apart at the base. 2. P. caudatum. 



1. Pteridium aquilinum (L.) Kuhn. Eootstock stout, woody, horizontal. Leaves 

 erect, sometimes 2 m. tall ; petioles straw-colored or brownish, 3-6 dm. long ; blades 6-12 

 dm. long, usually glabrous, ternate, the three divisions each 2-pinnate, the lower leaflets 

 more or less pinnatifid. [Pteris aquilina L.] 



In sunny places, throughout North America, Europe and Asia. Variable. BRACKEN. BRAKE. 



2. Pteridium caudktum (L. ) Maxon. Leaves erect, 1-4 m. tall, or sometimes taller ; 

 blades 3-4-pinnate ; divisions pinnatifid, the ultimate segments narrow, with recurved mar- 

 gins, remote from one another, scarcely decurrent on the rachis except near the apex, the 

 larger with 1-12 similar but shorter segments. [Pteris aquilina var. caudata (L.) Hook.] 



In sandy soil, Florida and Texas. Also in the West Indies. 



10. ADIANTUM L. 



Graceful plants of rocky hillsides, woods and ravines, with much divided leaf-blades. 

 Petioles and their divisions slender or filiform, polished and shining. Sori short, margi- 

 nal, borne on the under side of the reflexed and altered portion of the leaflets, which serves 

 as an indusium. MAIDENHAIR FERN. 



