FILICES. (FERNS.) C25 



4. PHLERODIFM, R. Br. Veins pinnate from the midrib, furcate: veinlets 

 reticulated in mostly elongated meshes. Fruit-dots large, commonly at the 

 extremities of two converging veinlets. 



6. P. aureum, L. Fronds smooth and glaucous, broadly ovate, pin- 

 nately parted ; the divisions lanceolate, acuminate, entire; fruit-dots mostly 

 in a double series in each lobe of the frond, near the midrib. South Florida. 

 Rootstock large, creeping, copiously beset with lanceolate brown chaffy 

 scales. Stipe smooth, 8'- 10' long. Fronds 10'- 15' long, two thirds as wide. 



5. PHYMATODES. Areolcejine, irregular, the free veinlets spreading in 



rarious directions. 



7. P. Swartzii, Baker. Rootstock very slender, long and climbing; 

 fronds single, or 2 - 3 together, 4' or 5' long, lanceolate, mostly obtuse, nar- 

 rowed at base into the short stipe, the margins wavy, entire ; sori in a single 

 row on the free veinlets. (P. serpeus, Swartz.) Key Largo, South Florida 

 (Curtiss), climbing on low bushes. 



3. TJENITIS, Swartz. 



Sori linear, continuous or interrupted, central or intramarginal. Veins 

 reticulate. 



1. T. lanceolata, R. Br. Rootstock thick, creeping ; frond 6' -12' long, 

 lanceolate, entire, narrowed at base into the short smooth stipe ; sori intra- 

 marginal along the upper part of the frond. On trees, Rhoda Key, South 

 Florida (Curtiss). 



4. VITTARIA, Smith. 



Sporangia on a continuous receptacle immersed in a furrow open outwardly 

 at or near the margin of the frond. Veins obscure, simple, connected at their 

 extremities by the receptacle. Fronds simple, linear, elongated. 



1. V. lineata, Swartz. Fronds nearly sessile, narrowly linear, elon- 

 gated; midrib inconspicuous, lines of fructification near the margin. (V. an- 

 gustif rons, Michx. ) On trees, South Florida. Fronds many from the short 

 scaly rootstock, l-2long. 



5. PTEBIS, L. 



Sporangia borne on a transverse marginal receptacle connecting the ends 

 of the veins. Indusium continuous, formed of the membranaceous margin of 

 the frond, at first reflexed, at length pushed back and disclosing the ripened 

 fructification. Fronds 1 - 3-pinnate or decompound. 



1. P. longifolia, L. Fronds lanceolate, pinnate ; pinnae numerous, nar- 

 rowly linear, acuminate, obtuse at the base, the terminal one elongated, the 

 lower ones gradually smaller. Key West. Fronds l-2 high, smooth. 

 Stipe more or less chaffy. 



2. P. Cretica, L. Fronds smooth, ovate, terna-te or pinnate; tbe lower 

 pinnte 2-3-parted, sessile, the upper ones decurrent; sterile ones lanceolate, 

 or linear-lanceolate, finely serrate ; fertile ones narrower, entire, or spinulose- 

 serrate at the acuminate apex ; veins straight, simple or forked, close together, 

 almost at right angles to the midrib. Shady woods, Middle and East Flor- 

 ida. Fronds 6'- 10' long. Stipe smooth, very long and slender. 



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