465 LYGODIUM. 



Tribe 2. OSMUNDIACE^. 



Tiieca: destitute of a ring, reticulated, striated ivith rays at the apex, opening lengthwise and 

 usually externally. 



11. OSMU'NDA. 



Thecae subglobosc, pedicellate, radiate-striate, half-2-valv- 

 ed, collected on the lower surface of the frond or a portion of 

 it, which is more or less contracted into the form of a panicle. 



* Fertile fronds distinct from the sterile. 



1. O. Cinnamo'mea. Cinnamon-colored Fern. 



Sterile frond pinnate, leaflets elongated, pinnatifid, segments ovate-oblong, 

 obtuse, very entire ; fertile frond bipinnate, leaflets contracted, paniculate, 

 subopposite, lanuginous ; stipe lanuginous. Tiiis is among the largest of our 

 ferns, growing in swamps and low grounds. Fronds numerous, growing in 

 clumps, 3 — 5 leet high, most of them barren, the stipe and raciiis invested 

 with a loose, cinnamon-colored wool. The fertile fronds resemble spikes, 

 1 — 2 feet long, an inch wide. Leaflets all fertile, erect, with the segments 

 covered with fruit in the form of small, roundish capsules, appearing, under a 

 microscope, half-2-cleft. June. 



* * Portions of each frond fertile. 



2. O. rega'lis. Royal Flowering-Fern. O. spectabilis. Willd. 

 Fronds bipinnate, fructiierous at the summit; segments of the leaflets lance- 

 oblong, distinct, serrulate, subsessile; raceme large, terminal, decompound. 

 A large and beautiful fern, in swamps and meadows. The fronds are 3 — 4 

 feet high, smooth in all their parts. Leaflets or pinnce opposite, remote, each 

 with 6 — U pairs of leaves with an odd one. These are an inch or more long, 

 i as wide, obtuse, the petioles — j line long. Above, the frond is crowned 

 with an ample bipinnate raceme of a deep fulvous hue, with innumerable, 

 small, globular, 2-valved thecse entirely covering the segments. June. 



3. O. Claytonia'na. L. 



Frond pinnate ; leaflets or yinnm pinnatifid, the upper ones contracted and 

 fertile. Smaller than either of the foregoing, found in swamps, Cambridge, 

 N. Y. Dr. Beck. Fronds 12 — 18 inches high. Pinnae oblong, obtuse, 2 — 4 

 inches long, tomenlose in the axils. Segments entire. Each frond bears a 

 terminal, bipinnate, lust-coIored, erect panicle, covered with fruit. May. 



4. O. INTERRU'PTA. 



Frond pinnate, smooth ; leaflets nearly opposite, pinnatifid ; segments oblong, 

 rather acute, entire ; some of the intermediate leaflets fertile. A large fern 

 in low grounds. Fronds 2 — 3 feet high, light green, interrupted near the 

 middle by 2 — 4 pairs of fertile leaflets, which are so much contracted in size, 

 as to resemble dense, compound racemes, and densely covered with small 

 reddish brown thecse. Stipe channeled, smooth above, chafty at base. June. 



12. LYGO'DIUM. 



Theca^. sessile, arranged in 2-ranked spikelets issuing from 

 the margin of the frond, opening on the inner side from the 

 base to the summit; indusium a scale-like veil covering each 

 theca. 



L. palma'tum. Sw. Climhing Fern. 



Stem flexuous, climbing ; fronds conjugate, palmate, 5-lobed, lobes entire, 

 obtuse; sjjikelets oblong-linear, from the upper fronds which are divided and 



