634 CLXIV. FILICES. Osmunda. 



united ; fertile fmids bipinnale, with recurved and globular contracted seg- 

 ments. — Common in low grounds. Fronds about a foot high, the barren ones 

 broad and somewhat triangular in outline, composed ot^ broad, oblong, sinuate 

 divisions, the upper ones smaller, nearly entire, becoming united at base. The 

 fertile Irond is very dissimilar in its form to the others, resembling a compound 

 spike, enclosing the fruit in the globular segffi.ents of its short divisions. Color 

 dark brown. July. 

 fi. obtv^ilobata.ToTr. (O. obtusilobata. Schk.) Z/te. opposite ; se^?«. rounded. 



12. STRUTHIOPTERIS. Willd. 



dr. orpovSos, the ostrich, vrcpov, wing, or plume ; from the resemblance. 



Tliecae densely covering the back of the frond ; indusia scaly, 

 marginal, opening internally. 



S. Germanica. Willd. (S. Pennsylvanica. Willd.) Ostrich Fern. 



Sterile fronds pinnate; leaflets pinnatifid, sessile; segments entire, rather 

 acute, the lower ones somewhat elongated. — A fern of noble size and appear- 

 ance, growing in low woods and swamps. The sterile fronds are often 5 or 6f 

 high, commonly about 3, numerous, in circular clumps. Stipes smoSth, chan- 

 neled ; leaflets pinnatifid, with numerous segments, the lower of which are the 

 more narrow and acute, all more or less connected at base. Fertile fronds fev/, 

 in the midst of the sterile, much smaller, the leaflets with numerous, brown- 

 ish, contracted segments, densely covered by the fruit beneath. Aug. 



Tribe 2. OSMUNDIACE^. — Thecal destitute of a ring, reticulated, stri- 

 ated with rays at the apex, opening lengthwise and usually externally. 

 13. OSMUNDA. 

 Thecae subglobose, pedicellate, radiate-striate, half-2-valved, collect- 

 ed on the lower surface of the frond or a portion of it, whicli is more 

 or less contracted into the form of a panicle. 



* Fertile fronds distinct from the sterile. 



1. O. CiNNAMOMEA. Cinnamon-colored Fern. 



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

 obtuse, very entire; fertile frond bipinnate', leaflets contracted, paniculate, sub- 

 opposite, lanuginous ; stipe lanuginous. — This is among the largest of our 

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

 clumps, 3 — 5f high, most of them barren, the stipe and rachis invested with a 

 loose, cinnamon-colored wool. The fertile fronds resemble spikes, 1 — 2f 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-clefl, June. 



* * Portions of each frond fertile. 



2. O. REGALis. Michx. (O. spectabilis. Willd.') Royal Flowering-Fern. 



Fronds bipinnate, fructiferous 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 — 4f high, 

 smooth in all their parts. Leaflets or pinnae opposite, remote, each with 6—9 

 pairs of leaves with an odd one. These are an inch or more long, i as wide, 

 obtuse, the petioles — J" long. Above, the frond is crowned with an ample 

 bipinnate raceme of a deep fulvous hue, with innumerable, small, globular, 

 2-valved thecae entirely covering the segments. June. 



3. O. Claytoniana. 



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

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

 N. Y., Dr. Beck, W. to Wise, Dr. Lapham ! Fronds 1— 2f high. Pinna; ob- 

 long, obtuse, 2 — 4' long, tomentose in the axils. Segments entire. Each frond 

 bears a terminal, bipinnate, rust-colored, erect panicle, covered with fruit. May. 



4. O. INTERRUPTA. Michx. 



Frond pinnate, smooth; leaflets nearly opposite, pimxatifld ; segments ob- 



