PoLysticHum ANDERSONI AND RELATED SPECIES 35 
1. Polystichum alaskense Maxon, sp. nov. 
Rhizome stout, ascending or decumbent, very densely 
paleaceous, the scales rich chestnut brown in mass, 
yellowish brown individually, concolorous, thin, trans- 
lucent, linear-attenuate to broadly ovate and long- 
acuminate, irregularly denticulate, 1.5-2 em. long. 
Fronds several, 50-90 cm. long, apparently forming 
a close crown; stipes stout, 8-22 em. long, strongly 
arcuate at the blackish base, deeply suleate, copiously 
Paleaceous, the scales extremely variable, minute and 
linear to Ovate-acuminate and 1.5 em. long, denticu- 
late; lamina 30-70 em. long, 9-18 em. broad near the 
middle, narrowly linear-lanceolate to linear-oblanceo- 
late, long-attenuate at both extremities, 3-5 cm. broad 
at the base, subbipinnate; rachis densely and _per- 
sistently paleaceous, the scales mostly small, linear 
* to lanceolate ; pinnae 25-40 pairs, close, mostly alter- 
hate, Spreading (those of the basal third somewhat 
(eflexed), straight or nearly so, the middle ones the 
largest, these 4.5-9 em. long, 1.5-2.5 em. broad, linear- 
oblong, acutish to long-acuminate, nearly pinnate In 
their basal half, pinnately cleft toward the apex; larger 
“sments 10-16 pairs, spreading, close or contiguous, 
oblong-ovate or rhombic-ovate, auriculate or mostly 
‘ubauriculate, subsessile to semiadnate and short- 
decurrent, serrate, the teeth curved and mostly ap- 
Pressed, tipped with stiff whitish awns, these 1-2 mm. 
long, Spreading or more commonly incurved over the 
Upper surface of the segment; midribs and lower suf 
faces fibrillose-paleaceous, the upper surface sparingly 
80, glabrescent ; sori 3-6 pairs, large, nearer the midrib 
: than the margin, borne on the basal branch of the 
‘ate, mostly once or twice forked veins; indusia 
dy Persistent, orbicular, pale with a darker seg 
*se-dentate, the teeth gland-tipped. Leaf tissue Tg? y 
herbaceous, Opaque, dull dark green above, paler beneath. 
