FiLicES. (ferns.) 597 



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

 and northward. — Fronds 6' - 16' high. 



17. DICKSONIA, L'Her. § SITOLOBIUM, Desv. 



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

 vated i-eceptacle in a thin cup-shaped involuerc which is partly adherent to a 

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

 stock. — DiCKSO\iA proper has large two-lipped involucres, of a firmer texture, 

 and several species have an arborescent caudex. 



1. D. punetilobula, Kunze. Fronds delicate, slightly glandular-pubes- 

 cent, as is tiie 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 tlie uj)per 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 recept^icle : 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-lauQColate or obovatc, entire or variously pinnatifid, nar- 

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

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

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

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

 from a waterfall, Hancock Co., Alabama, T. Af. 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 stijje, 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 cuncate ; divisions toothed or 

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

 tul)ular-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 

 nan'ow divisions of the fronds, attached laterally, ovate, with a many-rayed api- 



