1. Diplazium pycnocarpon (Spreng.) M. Broun (narrow-leaved glade
fern, narrow-leaved spleenwort) Pl. 4f,g,h; Map 20
Athyrium pycnocarpon (Spreng.) Tidestr.
Rhizomes prostrate, creeping. Rhizome scales concolorous, brown, lanceolate to
ovate. Leaves usually somewhat dimorphic, the fertile leaf blades with somewhat
narrower pinnae than those of vegetative leaves. Leaves 50–125 cm long.
Petioles shorter than the leaf blade, with scattered, brown scales, nearly
glabrous at maturity, the base with 2 vascular bundles. Leaf blades lanceolate
to narrowly elliptic in outline, 1 time pinnately compound. Pinnae 7–130 mm
long, lanceolate to linear, the tips attenuate, the margins entire or shallowly
toothed. Veins not anastomosing. Sori linear. Indusia attached laterally,
arching over the sori. Spores 64 per sporangium, monolete, 27–50 mm long, brown. 2n=80.
July–September.
Scattered in the Ozark and Ozark Border Divisions, and locally in counties
adjacent to the Missouri and Mississippi River
floodplains (eastern U.S.
and adjacent Canada west to Kansas). Mesic forests
in the bottoms of ravines and sinkholes, and in the valleys of streams, on a
variety of substrate types; infrequent along the edges of fens.