An Illustrated Flora of the Northern United States, Canada and the British Possessions/Osmundaceae

by Nathaniel Lord Britton & Addison Brown

Family 2.   Osmundàceae   R. Br.   Prodr. Fl. Nov. Holl. 1: 161.   1810.
Royal Fern Family.

Large ferns with creeping or suberect rootstocks. Stipes winged at Che base, the blades 1-2-pinnate or tripinnatifid, with free mostly forked veins extending to the margins. Sporanges naked, large, globose, mostly stalked, borne on modifie contracted pinnae and nearly covering them or (in Todea and Leptoptcns. Old World genera) in clusters (sori) on the lower surface of the pinnules or segments, opening in 2 valves by a longitudinal slit; ring wanting or mere traces of one near the apex.

Three living genera, Osmunda and the two mentioned.

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1.   Osmúnda   L.   Sp. Pl. 1063.   1753.

Tall swamp or lowland ferns, the leaves in large crowns, long-stalked, the blades bipinnatifid or bipinnate, with regularly forked prominent veins, the fertile portions much contracted and devoid of chlorophyl, the short-stalked sporanges thin, reticulated, opening in halves, a few parallel thickened cells near the apex representing the rudimentary transverse ring. Spores copious, greenish. [From Osmunder, a Saxon name for the god Thor.]

Eight species, the following in North America. Type species: Osmnnda regalis L.

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Blades bipinnate, some of them fertile at the apex.

1.

O. regalis.

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Herbaceous blades bipinnatifid.

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Pinnae of sterile blade with a tuft of tomentum at the base; blades normally dimorphous.

2.

O. cinnamomea.

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Pinnae of sterile blade lacking a tuft of tomentum at the base; blades normally fertile only in the middle.

3.

O. Claytoniana.

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1.  Osmunda regàlis  L. Royal Fern.   Fig. 15.
Osmunda regalis L. Sp. Pl. 1065.  1753.
Rootstock stout, bearing a cluster of several long-stalked leaves, 2°–6° high, the apical pinnae fertile, contracted, forming an upright terminal panicle, the pinnules linear-cylindric, greenish before maturity, dark brown and withering with age.  Sterile pinnae 6′–12′ long, 2′–4′ wide, the pinnules oblong-ovate or lanceolate-oblong, sessile or slightly stalked, glabrous, finely serrulate, especially near the apex and occasionally crenate toward the truncate, oblique, or even cordate, base.
In low woods, swamps and marshes, Newfoundland to Florida, west to Mississippi, Nebraska and Saskatchewan. Also in Tropical America, Europe and Africa.  May-July.  Called also Royal Osmond. Bracken, Buckhorn-brake. King's-, flowering-, water-, tree-, snake- or ditch-fern. Bog-onion, Herb Christopher, Hartshorn-bush.

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	2.  Osmunda cinnamòmea  L. Cinnamon-fern.   Fig. 16.
	Osmunda cinnamomea L. sp. Pl. 1066.  1753.
	Rootstock very large, widely creeping, bearing a circular cluster of sterile leaves with one or more fertile ones within.  Stipes 1° or more long, clothed with ferruginous tomentum when young, glabrous with age.  Sterile blades 1°–5° long, oblong-lanceolate, deeply bipinnatifid, the pinnae linear-lanceolate, deeply pinnatifid into oblong obtuse segments, the margins usually entire.  Fertile blade contracted, bipinnate, soon withering; sporanges cinnamon-colored.
	In wet woods, swamps and low grounds, Newfoundland to Minnesota, the Gulf states and New Mexico. Also in Mexico, Brazil, the West Indies and eastern Asia. Forms occur with leaves variously intermediate between the fertile and sterile.  May-June.  Bread-root. Fiddle-heads. Swamp-brake.

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3.  Osmunda Claytoniàna  L. Clayton's Fern.   Fig. 17.
Osmunda Claytoniana L. Sp. Pl. 1066.   1753. Osmunda interrupta Michx. Fl. Bor. Am. 2: 273.   1803.
Rootstock stout, creeping; leaves 2°-6° long, loosely tomentose when young, glabrous with age, the outer ones usually sterile and spreading, the inner erect and usually fertile in the middle. Blades oblong-lanceolate, 1°-4° long; sterile pinnae oblong-lanceolate, deeply cleft into ovate-oblong close or slightly imbricate segments, the margins usually entire; fertile pinnae 2-5 pairs, fully pinnate, the cylindric divisions very close, greenish at first, dark brown, brittle and withering with age.
In swamps and moist woods, Newfoundland to Minnesota south to North Carolina, Kentucky and Missouri. Ascends to 5000 ft. in Virginia. Also in China and India.  May-July.  Interrupted- or Clayton's-flowering-fern.