FILICES. (FERNS.) 593 
with a double indusium. — Mountains of Alabama, and northward. — Fronds 
2!—5! high, with a vind greenish rachis, and a stipe nearly as long as the 
frond. 
7. A. Ruta-muraria, L. Fronds small, ovate, pinnate above, bipinnate 
below, the divisions stalked, obovate-cuneate, toothed at the apex ; veins forked 
from the base ; fruit-dots few, indusia laciniate at the margin. — Rocks along 
the mountains, and northward. — Fronds 9! — 4! high. 
8. A. myriophyllum, Presl. Fronds delicately membranaceous, lan- 
ceolate, narrowed below, 2-3-pinnate; ultimate segments obovate-oblong, en- 
tire or 2-3-lobed; veins single in each segment or lobe, bearing below the 
» middle a solitary oblong fruit-dot. (A. Anchorita, Chapm. MS.) — On the walls 
of a limestone cave at Schurlock's Spring, Jackson Co., Florida, Chapm.— 
Fronds 3' —10' high, with short stipes and narrowly winged rachises. 
9 A. thelypteroides, Michx. Fronds ‘ample, oblong-ovate, pinnate; 
the deeply pinnatifid pinnæ lanceolate-acuminate from a broad sessile base; the 
lower ones smaller, distant, and deflexed; the lobes oblong, obtuse, crenately . 
serrate; fruit-dots 8-12 to a lobe, at length confluent, those next the midrib 
toward the ends of the pinos mostiy double ; indusium, convex, thickish. — 
ne "o T ard. inte ui "Hai ad . 
$2. ATHYRIUM, Roth.—Indusium thin, attached to T suis ofthe wa vein 
or recurved and crossing the vein, attached to both sides of it, thus becoming reni- 
form or shaped like a horseshoe. 
10. A. Filix-foemina, Bernh. Fronds ee ovasechbings pinne lan- è 
ceolate, numerous; pinnules oblong or lanceolate, doubly serrate or variously 
incised ; fruit-dots short, at length confluent. (Aspidium Filix-fæmina, Swartz.) 
— Low shady woods, Florida to Mississippi, and northward. — Fronds 19-39 
high. — A. asplenoides (Aspidium asplenoides, Swartz?) is said to differ in hav- 
jug a creeping caudex. 
iii CYSTOPTERIS, Bernhardi. 
Fruit-dots round, on the back of the free forkiug- veins, pics, ‘when. ‘young 
by a thin ovate or roundish hood-shaped indusium attached by the lower side - 
rather beneath the fruit-dot, its apex pointing toward the end of the vein, at 
length reflexed or falling away. — Delicate Ferns with 2-3-pinnate fronds, and 
_ short creeping rootstocks. 
. 1. C. fragilis, Bernh. rod niin bipinnate; the ovate-lance- 
olate pinnz mostly opposite, the lowest pair distant, smaller; pinnules oblong 
or obovate, cuneate at the base and decurrent on the winged secondary rachis, 
variously toothed or incised ; indusium ovate, acuminate. (Aspidium tenue, 
Swartz.) . " Moist rocks on the mountains of North entios, 2 — 
