CHAPTER X 
CHRISTMAS FERN 
Polystichum acrostichoides. 
Rootstock creeping, chaffy: scales pale brown, lanceolate or 
ovate, acuminate, slightly ciliate: leaves clustered at apex of 
rootstock: roots springing from rootstock or extreme bases of 
petioles. 
Leaves ascending, five to twenty-seven inches long, two and 
four-fifths to four and four-fifths inches broad, imperfectly ever- 
green; in autumn prostrated, the fertile parts of sporophylls 
usually withering. 
Petioles shorter than blades, two to six and two-fifths inches 
long, toward base dark, often reddish or lighter brown, above 
green, somewhat flattened or furrowed on face, turgid at base, 
chaffy: scales numerous, pale brown, ovate or lanceolate, acu- 
minate, ciliate: fibrovascular bundles four or five; the two 
anterior largest, ovate-wedge-shaped or suboval in section, or 
slightly hollowed on one or both sides; the others ellipsoidal or 
roundish in section. 
Blades rigid, lanceolate, pinnate; apex pinnatifid, becoming 
serrate or serrulate at tip, subacute or acute or acuminate: pinne 
mostly approximate or in sporophylls distant, alternate or oppo- 
site, mostly subsessile or very short-stalked, obtuse or acute or 
