Blechnum L.
Sori elongate, || costa, one on each side; indusium opening towards costa, firm, elongate. Sporangia rather large, crowded; annulus vertical, incomplete. Spores bilateral, reniform to subglobose, us. smooth. Rhizome dictyostelic, paleate, erect or ascending, sts forming a distinct caudex; or rhizome creeping, sts scandent. Fronds us. pinnate to pinnatifid, us. coriac. Over 200 spp., mainly of the southern hemisphere.
Key
10
Pinnae of fertile fronds connected by widened base; plant stoloniferous; sterile lamina whitish or reddish brown on under surface; up to 1 m. or more tall, erect
Pinnae of fertile fronds not connected by widened base; plant not stoloniferous; sterile lamina not markedly discolorous, if reaching 1 m. then spreading or drooping
13
Pinnae of fertile laminae 5-8 cm. long; pinnae of sterile laminae up to 4-8 cm. long, falcate, acuminate; plant up to 1 m. tall
Pinnae of fertile laminae 1-4 cm. long; pinnae of sterile laminae up to 2-5 cm. long, lanceolate, acute to obtuse
14
Pinnae of fertile laminae connected by widened bases; sterile lamina markedly discolorous; plant forming very large clumps, stoloniferous
Pinnae of fertile laminae not connected by widened bases; sterile lamina not markedly discolorous; plant not forming very large clumps, not stoloniferous
15
Sterile lamina with up to 50 pairs of distant, opp. to subopp., oblong to suborbicular pinnae; fertile lamina with the pinnae erect or ascending
18
Fronds 20-75 cm. long or more; sterile pinnae 2-6 cm. × 10-15 mm., narrow-oblong to lanceolate
19
Sterile pinnae rather coarsely dentate-serrate, up to 12-20 mm. long, of oblong order, obtuse; lower pinnae in rather distant pairs
Sterile pinnae sinuate-crenate to almost entire, up to 2-6 cm. long, of lanceolate order, bluntly to acutely pointed; lower pinnae approximate to confluent