50 
POLYrODIACE.?J — PTERIDE.?:. 
entire margin of the fronds, sporangiferous on its under surface, at length replicate. Costa excentric 
or wanting ; veins unilateral, or radiating, forked ; venules direct, terminating in the axis of the indu- 
sium. Fronds simple reniform, pinnate, pedate, bipinnate or decompound, from six inches to two or 
three ieet high, smooth or hairy. Stipes and rachis usually ebeneous ; pinnm generally oblique, 
truncate or cuneate at the base, or dimidiate and soriferous on the upper margin only, petiolate, and 
usually articulated with the rachis or petiole. — Named from adiantos, dry ; alluding to a curious 
property of the fronds, which repel moisture. 
This very extensive and natural group contains upwards of 
a hundred known species, of graceful form, whose ebeneous 
slenderj shining stipes and rachis contrast admirably with 
the pinnce, which are of a very delicate green colour. They 
have a very extensive geographical range, being found in the 
tropical and subtropical regions of both hemispheres, as well 
as in Europe, New Zealand, and North America. They have 
a very close affinity with Cheilanthes and Hewardia, the latter 
a genus not in cultivation. From the former they are distin- 
guished by the position of the soil, which in Cheilanthes are 
situated on the apex of single venules in the axis of the indu- 
sium, whereas in Adiantum the sorus is placed on the indusium. 
From Heivardia they are distinguished by the latter having a 
reticulated venation. Fig. 32 represents a small portion of a 
frond of Adiantum tenerum (nat. size). 
1. A. IU5NIF0RME, — [Plate IV.] — Linnaeus . — A dwarf evergreen 
greenhouse Fern, from Madeira, and the Azores and Canaries. Fronds 
simple, round or reniform, glabrous, bright shining green, about six 
indies high, terminal, adherent to a scaly, somewhat creeping rhizome. Soil oblong, contiguous. 
2. A. WiLSOXi, Hooker . — An evergreen stove Fern, from Jamaica. Fronds glabrous, one foot long, simple, 
pinnate ; pinnse ovate or oblong-acuminate, coriaceous, shining green, cordate at the base ; the sterile ones broad, 
serrate at the margin, petiolate, persistent and not articulate with the rachis ; fertile fronds with from three to 
five pinnse. Soil linear, continuous. Fronds lateral, adherent to a creeping rhizome about the size of a duck’s 
quill. 
3. A. MACRoruYLLUM, Swavtz . — A very beautiful evergreen stove species, from the West Indies and tropical 
America. Fronds glabrous, oblong-acuminate, broad at the base, pinnate, one to one and a half foot long ; pinnae 
large, ovate or oblong, sub-sessile, acuminate, cbartaceous, of a lively green, unequally cuneate at the base, the 
sterile ones lohed and slightly dentate. Soil linear, continuous. This is rather an erect-growing plant, with 
the fronds lateral, adlierent to a creeping rhizome. 
4. A. LUciDUM, Sivartz . — A glabrous evergreen stove Fern, native of the West Indies and South America. 
Fronds lanceolate, pinnate, one foot long ; pinnDe trapezio-lanceolate, acuminate, coriaceous, bright green, shining, 
truncate, and parallel with the rachis at the upper base, the lower cuneate, the margin serrate. Eachis and 
stipes very hairy ; lateral, adherent to a slender creeping rhizome. Soil linear, continuous, or sometimes 
interrupted. 
5. A. Kaulfussii, Kitnze (A. OBLiauuM, Hooker and Oreville, not WilMenoio — fide Hooker '). — A glabrous 
evergreen stove species, from tbe West Indies and South America. Fronds lanceolate, pinnate, one foot long ; 
pinna? ovate-ohlong, acuminate, deep green on the upper surface, and glaucous beneath, the inferior base trun- 
cate, the superior rounded and slightly auriculate, margin serrate. Sori oblong, linear, numerous throughout 
each fertile pinna. Fronds nearly all fertile, lateral, adherent to a slender creeping rhizome. Eachis and stipes 
hairy. 
6. A. LUNULATUM, Bumiami (A. arcuatum, Swartz ). — An elegant, deciduous stove Fern, from the East Indies, 
Ceylon, Africa, and South America. Sterile fronds glabrous, pinnate, pendulous, a foot or more long, and rooting 
at the apex ; pinnse oblong-dimidiate, bright green, lobed on the upper margin, and obtuse at the base. Fertile 
fronds erect, narrow-lanceolate, a foot or more long, glabrous, pinnate ; pinnse with long petioles, lunate on the 
upper margin, truncate-cuneate at the base. Sori oblong-linear, often confluent. Fronds terminal, adherent to 
a fasciculate rhizome. 
7. A. CAUDATUM, Linnaeus (A. iiirsutum, Lory; A. flagelliferum, Wallich ). — A neat evergreen stove 
species, from India, Ceylon, China, and the Mauritius. Fronds haiiy, narrow linear-lanceolate, elongate. 
