I02 OUR NATIVE FERNS AND THEIR ALLIES. 



XVII. BLECHNUM L. 



Sori linear, continuous or nearly so, parallel with the midrib 

 and usually contiguous to it. Indusium membranous, distinct 

 from the edge of the frond. Veins usually free. Name from 

 Gr. pXexvov, an old name for some kind of fern. A tropical and 

 south temperate genus, containing 19 species. 



§ EUBLECHNUM. 



I. B. serrulatum Richard. Stipes 6'^I2' long, stout, 

 erect, nearly naked; fronds oblong-lanceolate, 1° — iy° long, 

 3' — 6' broad, with 12 — 24 pairs of distinct linear-oblong pinna;, 

 the margins finely incised ; texture coriaceous ; veins very fine 

 and close; fertile pinnae narrower. {Blechnum angustifoUum 

 Willd.) Florida. 



XVIII. WOODWARDIA Sm. Chain-fern. 



Sori oblong or linear, sunk in cavities in the frond, arranged 

 in a chain-like row parallel to the midribs of the pinnae and 

 pinnules and near them. Indusium sub-coriaceous, fixed by its 

 outer margin to the fruitful veinlet and covering the cavity like 

 a lid. Veins more or less reticulate. Named for Thomas J. 

 Woodward, an English botanist. Contains six species, mostly 

 north temperate. 



§ I. EuwoODWARDiA. Fronds uniform, the Veins forming 

 at least one series of areola between the sori and margins. 



1. W. radicans (L.) Sm. Caudex stout, erect, rising a little 

 above the ground ; stipes stout, 8' — 12' long ; fronds 3° — 5° 

 long, sub-coriaceous, pinnate; the pinnae 8' — 15' long, 2' — 4' 

 broad, oblique to the rachis, pinnatifid nearly to the midrib ; 

 segments spinulose-serrate ; veinlets forming a single row of 

 oblong sorus-bearing areolae next the midvein, besides a few 

 oblique empty areolae outside the fruiting ones, thence free to 

 the margin. California, Arizona. 



§ 2. Anchistea Presl. Fronds uniform, the veins free be- 

 tween the sori and the margins. 



2. W. Virginica (L.) Sm. Stipes stout, 12' — 1_8' long; fronds 

 oblong-lanceolate, 12'— 18' long, 6'— 9' broad ; pinnae linear- 

 lanceolate, 4' — 6' long, f — i' broad, cut nearly to the rachis 

 into linear-oblong lobes. ( W. Banisteriana Michx., Blechnum 



