250 43. ASPIDIUM, § POLYSTtCIIUM. 



point acute, the edge finely not spinosely serrated, the upper side bluntly 

 fturicled, the lower obliquely truncate at the base ; texture very coriaceous ; 

 racMs usually scaly ; veins inconspicuous ; sori in two long rows. Hh. Sp, i. 

 p. 10. Fil. Eie. t. 53. 



Hah. Madeira.— P. maderense, Johnst. (Ann. N. H. April, 1866), is a form with 

 pinnse pinnate at the ba-e. 



7. A. (Polyst.) acrosticheides, Swz. ; at. 6-8 in. 1., densely clothed below with 

 pale-brown lanceolate scales ; fr. l-|-2 ft. 1., 3-5 in. br., the pinnce of the lower 

 half barren, 2-3 in. ]., J in. br., spinoso-serrated throughout, auricled at the 

 base above, the pinnse of the upper half fer,tile, much smaller ; texture sub- 

 coriaceous ; rachis straw-coloured, usually rather scaly ; veinlets in groups of 

 four ; sori occupying the whole under side of the fertile pinnse. — Hk. Sp. 4. p. 9. 



Eab. Canada to Florida and the Mississippi. ^-.i. Schweinitzii, Beck, is a form with 

 lobed pinnse. ^ 



8. A. (Polyst.) lepidocaulon, Hk. ; st. tufted, 6-9 in. I., weak, densely clothed 

 with large cordate brown scales '; fr. 1 ft. or more 1., 4-6 In. br., sometimes 

 elongated and radicant at the point ; pinnce 2-S in. 1., ^-j in. br., lanceolate- 

 falcate, not toothed, the two sides unequal, the upper ones with a triangular 

 auricle at the base ; texture subcoriaceous ; rachis densely scaly like the stipe, 

 lower surface with scattered scales ; veins obscure, sometimes slightly con- 

 nected ; sori principally in two rows a short space from the midrib. — Hk. Sp. 4. 

 p. 12. t. 217. 



Hab. Japan and Tsus-Sima. — Habit and texture of A, falcatwm, but the veins only 

 casually joined, and the racbis densely scaly. 



9. A. (Polyst.) Lonchitis, Swz. ; st. densely tufted, 1-4 in. 1., ebeneous and 

 clothed with large lanceolate pale-brown scales at the base ; fr. 12-18 in. 1., 

 1-2 in. br., pinnate throughout ; pinnce ^-1 in. 1., ^§ in. br., ovate-rhomboidal, 

 subfalcate, the two sides unequal, the point mucronate, the edge spinuloso- 

 serrated, the upper side sliarply auricled at the base, the lower obliquely 

 truncate ; rachis nearly naked ; textwe coriaceous ; sori usually in two rows. — 

 Hk. Sp. 4. p. 8. Brit. F. t. 9. 



Hab. Arctic Europe to Portugal, Naples, Greece, Himalayas, and Davuria ; Green- 

 land, and mountains of the N. United States, and British America. 



10. A. (Polyst.) mucronatum, Swz. ; st. tufted, 2-4 in. 1., stout, erect, densely 

 clothed with large reddish-brown lanceolate scales ; fr. 12-18 in. 1., 1^-2 in. 

 br., pinnate throughout ; pinnm very numerous, often imbricated, |-1 in. 1., 

 J-^ in. br., subrhoraboidal, unequal-sided, the point mucronate, the edge sub- 

 entire or slightly lobed, distinctly auricled at the base on the upper side ; 

 texture very coriaceous ; rachis stiff and densely scaly ; sori in a long row on 

 each side the midrib. — Hk. Sp. 4. p. 9. t. 216. 



Hab. West Indies, — Very like the preceding in appearance and texture. 



11. A. (Polyst.) lachenense, Hk. ; St. densely tufted, 2-4 in. ]., stout, 

 ebeneous, and clothed with large lanceolate scales below ; fr. 4-8 in. 1., J-| in. 

 bi-., pinnate throughout ; pinnce J-f in. 1., 2-3 lin. br., ovate-deltoid, the two 

 sides equal, the point bluntish, the edge spinoso-serrated, bluntly lobed below 

 halfway down; texture coriaceous; rachis stramineous, fibrillose ; sori often 

 covering the whole under side of tlie pinnse. — Hki Sp. A. p. 8. t. 212. 



Hab. Sikkim, Himalayas (13-16,000 ft.) ; gathered by Drs. Hooker, Thomson, and 

 Anderson. 



12. A. (Polyst.) triangulum, Swz. ; st. tufted, 2-6 in. 1., with large dark- 



