FILICES. 91 



** Lower pinnce forked or slightly pinnate below. 



2. P. Cretica L. Stipes 6' 12' long, erect, stramineous 

 or pale-brown; fronds 6' 12' long, 4' 8' broad, lateral pinnae 

 usually in 2 6 opposite sessile pairs, the sterile ones considera- 

 bly the broadest and spinulose-serrate, the lower pairs often 

 cleft nearly to the base, into two or three linear pinnules ; veins 

 fine, parallel, simple or once forked ; indusium pale. Florida. 



3. P. serrulata Linn. f. Stipes 6' 9' long, naked, pale 

 or brownish ; fronds 9' 18' long, 6' 9' broad, ovate, bipinna- 

 tifid, the main rachis margined with a wing which is i" 2" 

 broad at the top and grows narrower downwards ; pinnae in six 

 or more distinct opposite pairs, upper ones simple, the lower 

 ones with several long linear pinnules on each side, the edge of 

 the barren ones spinulose-serrate ; veins simple or once forked. 

 Alabama (Mokr), Macon, Georgia (Farnell}. 



2. P^ESIA St. Hilaire. Veins free, rootstock creeping, stipes 

 sub-distant, indusium more or less double. 



4. P. aquilina L. Rootstock stout, wide-creeping, subter- 

 ranean ; stipes i 2 high, erect, stramineous or brownish; 

 fronds 2 4 long, i 3 wide, ternate, the three branches each 

 bipinnate ; upper pinnules undivided, the lower more or less 

 pinnatilid. North America everywhere. 



Var, caudata Hook. Pinnules sometimes linear and en- 

 tire, or with less crowded segments than the type and the ter- 

 minal lobe linear and entire. (P. caudata L.) New Jersey to 

 Florida and Texas. 



Var. lanuginosa Hook. Fronds silky-pubescent or to- 

 mentose, especially on the under surface ; otherwise as in the 

 typical form. (P. lanuginosa Bory.) Utah, California and 

 northward. 



IX. CHEILANTHES Swz. LiP-FERN. 



Sori terminal or nearly so on the veins, at first small and 

 roundish, afterwards more or less confluent. Indusium formed 

 of the reflexed margin of the frond, roundish and distinct, or 

 more or less confluent. Veins free. Name from Gr. ^etAo?, a 

 lip, and arQo?, flower, alluding to the lip-like indusia. A 

 genus of 65 species of tropical and temperate zones. 



