10 
FERNS OF THE Vi^EST. 
vided with an incomplete ring, by whose contraction in ripening the 
spore-case is split open and discharges the minute spores. 
* Fruit-dots without iudusium or involucre. 
Fruit-dots roimd or roundish^ placed between the midrib and margin 
on the ends of the veins. 
Tribe I. — POLYPOBIEJE.— i. Polypodium. 
4 — Fruit-dots round, borne on the back of the veins., Indusium none, 
or minute or on the imder side of the fruit-dot, and so not evident. 
Phegopteris and Woodsia in Tribe VI. 
d — Fruit-dots either in lines along the veins, or in lines along the tips 
of the veins close to the margin. 
Tribe IL— aPAMMIlTDEI^. 
2. CrymilOgrailime. — Fruit-dots in lines along the veins. 
3- Notiiolsoiia. — Fruit-dots clustered at the tips of the veins along the margin, 
and so running in a more or less interrupted line around the edge. 
The margin slightly recurved in N. Candida, N. Grayi, N. Hookeri and so approaching Cheil- 
anthes, but these three species are white- or yellow-powdery beneath ; Cheilanthes never. 
* * Fruit-dots at the ends of the veins, with involucre at least when young. 
Tribe III.— PTERIDEJE. 
4. Elieilautlies. — Fruit-dots minute, involucre usually not continuous around 
the final divisions. 
Fronds hairy, woolly, or chaffy when the involucre is continuous. Small ferns, 
5. Pellsca. — -Fruit-dots close to the ends of the veins, often running together; 
involucre thin, continuous around the final divisions. Sterile and fertile fronds much 
alike, smooth, rather lead-colored; stalk black. 
6. Cryptogramme. — Fruit-dots inclined to run down the veins from their tips ; 
involucre broad, light-colored, flattening out as the fern matures. Sterile and fertile 
fronds unlike ; stalk light-colored. ^ ^ 
7. Pteris. — Spore-cases borne on what appears to be a vein running across the 
tips of the veins all around the division of the frond. Involucre continuous. Stalk light- 
colored. Large ferns, two to six feet high. * 
8. Adiailtlim. — The stalk of the final division (unlike the rest of the tribe) 
branching at the top into many veins, which run to the edge of the division like the rays 
of a fan, therefore no midrib. Outer edge of the final divisions recurved, forming the 
involucre. 
*** Fruit-dots with indusium (except Nos. 12 and 15 apparently.) 
4— Fruit-dots borne on the upper side of a veinlet (or a long receptacle 
which resembles it). Indusium attached to the veinlet and open on the 
other side, so forming a pocket for the spore-cases. 
Fruit- dots rather or very long, straight, parallel with the midrib. 
Tribe IV.— BLECmEAE. 
9. Lomaria. — Fruit-dots running the whole length of the pinnae. Fertile and 
sterile fronds pinnate narrow, unlike. 
10. Woodwardia. — Fruit-dots short, forming a chain-like row on each side of the 
midrib. Fronds large, broad. 
-FH- Fruit-dots straight or curved, short, borne on veinlets that are not 
parallel with the midrib. 
