Coarse lowland ferns with dissimilar leaves in a close crown upon a stout ascending rootstock. Sterile leaves tall, in a complete circle, the shorter fertile leaves appearing late in the season, borne within, rigidly erect, the pinnae closely contracted into necklace-like or pod-like divisions, these concealing the sori, finally dehiscent. Sori roundish, on elevated cylindrical receptacles, partly covered by delicate fugacious lacerate indusia attached below. [Named in honor of Carlo Matteucci, an Italian professor of physics.]

Species 3, the following, which is the generic type, and 2 Asiatic species.

1. Matteuccia Struthiopteris (L.) Todaro. Ostrich-Fern

Fig. 22

Osmunda Struthiopteris L. Sp. PI. 1066. 1753. Onoclea Struthiopteris Hoffm. Deutsch. Fl. 2: 11.

I795. Struthiopteris germanica Willd. Enum. 1071. 1809. Matteuccia Struthiopteris Todaro, Giorn. Sci. Nat.

Palermo 1: 235. 1866.

Rootstock stout, ascending, with slender underground stolons. Fertile leaves 1°-1 1/2° high, the pinnae dark brown, slightly crenate, contracted, with closely and widely revolute margins, the included sori crowded and confluent. Sterile leaves 2°-7° high, 6'-15' broad, broadly oblan-ceolate or spatulate, abruptly short-acuminate, gradually narrowed below the middle, the lower pinnae greatly reduced; pinnae narrow, deeply pinnatifid, glabrous, the segments oblong, obtuse, entire.

In moist thickets, especially along streams. Nova Scotia to Virginia, west to Brit'sh Columbia and Iowa. Ascends to 2000 ft. in Vermont. Also in Europe and Asia. July-Oct.