Polystichum acrostichoides (Michx.) Schott - Christmas Fern
Polystichum acrostichoides (Michx.) Schott
Family - Dryopteridaceae
Stems - Rhizomes horizontal, prostrate, with long fibrous roots, compact, sometimes branched. Scales of rhizomes brownish-orange, ovate to linear-lanceolate. Leaves terminating rhizome.
Leaves - To 75cm long, slightly dimorphic, pinnate. Pinnae sub-opposite near base, becoming alternate, serrate (the teeth mucronate), to +5cm long, +1cm broad, lanceolate, typically with a single acute auricle at the base, deep green and glabrous adaxially, lighter green and with tan scaly hairs abaxially. Pinnae of the upper 1/3 of leaf reduced, fertile. Rachis densely scaly (especially at the base). Scales tan, becoming hair-like near apex of leaf. Petiolule of pinnae short, to .5mm long.
Sori - Circular, ferruginous, almost completely covering the abaxial surface of the fertile pinnae. Indusia circular, peltate, to 1.5mm in diameter, scarious. Spores 64 per sporangium.
Abaxial surface of pinna showing sori.
Fiddle heads of young plants.
Flowering - June - October.
Habitat - Wooded slopes, in mesic and dry-mesic forests.
Origin - Native to U.S.
Other info. - This species can be found throughout Missouri and is probably the most common fern seen in the state. The leaves recline near the end of the year but remain green throughout the winter. The common name, "Christmas Fern", is so given because the plant stays green all year and because the pinnae resemble small Christmas stockings.
Photographs taken in Brown Summit, NC., 8-13-02.