FILICES. (FERNS.) 597 



hidden by the ripened sporangia. Rocky places, North Carolina, Tennessee, 

 and northward. Fronds 6' - 16' high. 



17. DICKSONIA, L'Hcr. SITOLOBIUM, Desv. 



Fruit-dots small, globular, terminal on the free veins ; sporangia on an ele- 

 vated receptacle in a thin cup-shaped involuere which is partly adherent to a 

 reflexed lobule of the frond. Fronds large, 2-3-pinnate, from a creeping root- 

 stock. DICKSONIA proper lias large two-lipped involucres, of a firmer texture, 

 and several species have an arborescent caudex. 



1. D. punctilobula, Kunzc. Fronds delicate, slightly glandular-pubes- 

 cent, as is the rachis, lanceolate-acuminate, 2 - 3-pinnate ; pinnae numerous ; 

 pinnules oblong-ovate, closely placed, obtuse, pinnately incised or pinnatifid ; 

 the divisions obtusely serrate, each one bearing a minute fruit-dot at the upper 

 margin. Moist shady woods in the upper part of North Carolina, Tennessee, 

 and northward. Rootstock slender, extensively creeping. Fronds 2 - 3 high, 

 when crushed returning a pleasant odor. 



18. TRICHOMANES, L. 



Sporangia with a transverse entire ring, arranged on the lower part of a 

 cylindrical, filiform, often elongated receptacle : involucres marginal, funnel- 

 shaped, or bell-shaped, entire or two-lipped at the mouth. Fronds delicate, very 

 thin and pellucid. 



1. T. Petersii, Gray. Very small, with entangled filiform tomentose root- 

 stocks ; fronds oblong-lanceolate or obovate, entire or variously pinnatifid, nar- 

 rowed into a slender stipe nearly as long as the frond, the younger ones with a 

 feV black forked hairs along the margin; veins forked, pinnate from the midrib; 

 involucre solitary, terminal, funnel-shaped, the mouth expanded and slightly 

 two-lipped, receptacle included. On the face of a sandstone rock, sprinkled 

 from a waterfall, Hancock Co., Alabama, T. M. Peters. Also among some 

 Mosses sent from Pensacola, Florida. Fronds less than an inch high. 



2. T. radicans, Swartz ? Fronds pellucid, with a loose roundish areola- 

 tion, on a short broadly winged stipe, lanceolate or ovate-lanceolate, bipinnatifid ; 

 pinnae ovate or deltoid-ovate, obtuse, the upper side of the base parallel and 

 appressed to the winged rachis, the lower side cuneate ; divisions toothed or 

 divided into linear lobes ; involucres terminal on short lobes of the pinnae, 

 tubular-funnel-shaped, margined, at the mouth truncate and slightly two-lipped; 

 receptacle exserted a little or very much. (T. Boschianum, Sturm.} Hancock 

 County, Alabama, Peters, Beaumont. Cumberland Mountains, Eastern Tennes- 

 see, Rev. Dr. Curtis. Rootstock slender, creeping, tomentose with black hairs. 

 Fronds 4' -8' high, 12" -18" wide. 



19. LYGODIUM, Swartz. CLIMBING FERN. 



Sporangia beneath ovate hood-shaped imbricated indusia, in a double row on 

 narrow divisions of tho fronds, attached laterally, ovate, with a many-rayed api- 



