DESCRIPTIONS OF THE SPECIES 115 
40. P. aristatum. Frond four-pinnatifid, lower pinnae deltoid ; 
teeth bristle-pointed. 
41. P. Macleaii. Frond simply pinnate, coriaceous ; sori in regular 
lines, or somewhat scattered. 
36. POLYSTICHUM ACULEATUM (Linn.) Schott. 
Plate 26. Nat. size. 
Plants growing singly, not in mass. 
Crown procumbent, abundantly paleaceous, elongating into 
a thick rhizome several inches long, set all round with the 
stipes of decayed fronds, from whose bases roots are freely 
given off. Fronds spreading two-pinnate or casually three- 
pinnatifid, softly herbaceous, varying from one to four feet 
long, six to twelve inches broad ; rather less or deflexed below, 
and with a stout stipe six to twelve inches long, which is 
abundantly paleaceous, with large, pointed, laciniate, brown 
scales at the base, and set with shorter, brown or red, woolly, 
scarious scales upward and throughout the rachis and secondary 
rachises. Pinnae three to six inches long, lanceolate, about an 
equal breadth (three-quarters to one and a half inches) for 
half the distance from the base to the point, then tapering. 
Pinnules sessile or shortly stalked, numerous, lax, one-sided, 
sharp-pointed, deeply toothed on the upper and outer edges 
with bristle-pointed teeth, or usually cut more or less into 
toothed lobes. Sori small, numerous. The pinnules differ 
very much in form, position, cutting, etc., in different forms, 
but intermediate varieties are to be found all through. The 
same plant in shade and in sun, or under a stone and on a 
stone, shows most of the variations that occur, and they cannot 
be separated nor perpetuated. 
Much confusion has existed between this species and the 
next. 
Buchanan, Wood, and Lady Barkly introduce A. acu- 
leatum Sw. as distinct from A. pungens ; and Pappe and 
Rawson so introduce P. angulare\ but I had such strong 
doubts about their distinctness that in my first edition all 
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