FIUCES. 91 



** Lower piivuv forked or sligJitly pinnate beloiv. 



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

 or pale-brown; fronds 6' — 12' long, 4' — 8' broad, laieral 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 

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



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

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

 tilid, the main racliis 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, tlie lower 

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

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

 Alabama {Mohr), Macon, Georgia {Farnel/}. 



§2. P.-E.SIA St. Hilaire. Veins free, rootstock creeping, stipes 

 sub-distant, indusitan more or less dotible. 



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

 ranean ; stipes 1° — 2" high, erect, stramineous or brownish; 

 fronds 2" — 4° long, 1° — 3" wide, ternate, the three branches each 

 bipinnate ; upper pinnules undivided, the lower more or less 

 pinnatiikl. North America everywhere. 



]'ar. caudata (L.) Hook. Pinnules sometimes linear and 

 entire, or with less crowded segments than the type and the 

 terminal lobe linear and entire. {P. caudata L.) New Jersey 

 to Florida and Texas. 



Var. lanuginosa (Bory) Hook. Fronds silky-pubescent, 

 tomentose, especially on the under surface ; otherwise as in 

 the typical form. {P. lanuginosa Bory.) Utah, California and 

 northward. 



IX. CHEILANTHES Swz. Lir-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. x^^^'^'^^ a 

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

 genus of 65 species of tropical and temperate zones. 



