267 



a. var. Size and form of the type, but apex of the fronds retuse and 

 viviparous. 



b. var. Pinnae in. 1 deeply inciso-dentate and spinulose, the auricle 

 deep but not free. — Polystichum laxum, J. Sm. 



c. var. Pinnae not reduced at the base of the frond, stipitate, ovate, 

 f-Jl in. 1. 6-7 li. w. above the auricle, which is fully connected or more 

 or less free, forming an ovate segment, margins freely spinulose dentate. 



Common on rocks and dry banks from 2,000-6,000 ft altitude, gene- 

 ral in elevated districts all through the country. A very variable species 

 The variations, speaking only of the forms here associated with the type 

 occur in the size of the frond ; the size and shape of the pinnae, and the 

 degree of their spinescent dentation. There is a small prostrate state, 

 with few pinnae, only 2 or 3 in. 1. hardly spinulose at the angles. In 

 some forms the pinnae are flat ; in others they are undulate with the 

 spiny teeth projecting at different angles, which give the leaflets a very 

 holly-like aspect. In this species too, the sori often turn black at ma- 

 turity. Variety b is Fig. 1 of Sloane's History t. 36. Some of the fol- 

 lowing plants, associated here with this species might well, seen above, 

 be regarded as distinct, but the numerous links show that they are only 

 modifications of this type. One or two of them run almost into aculea- 

 tum, from which the rigid texture is about the most reliable distinguish- 

 ing character. 



7. A. tridens, Hook. — Rootstalk oblique or upright, densely clothed with 

 blackish scales ; stipites densely tufted, slenderish, 3-6 in. L the upper 

 scales becoming brown ; fronds pinnate or bi-pinnate spreading, linear- 

 lanceolate, acuminate, base not reduced, 6-12 in. 1. 1-2 in. br. very rigid ; 

 pinnae very numerous, cuneate-stipitate, tri-partite the central segment 

 much the largest and inciseo- dentate at the base, as also are the spread- 

 ing lateral ones in the larger fronds, the parts sharply spinulose.- -A. 

 tridens, Hook. sp. Fil. vol. 4 t. 215. 



On dry banks in the Port Royal Mountains from 2,500-4,000 ft. alti- 

 tude ; gathered near Arntully Gap, 2,500 ft. alt. a peculiar, pretty plant, 

 usually very uniform and definite in its characters, still varying some- 

 what, and very distinctly of the triangulum group. In small fronds the 

 pinnae are nearly trifid, but in the larger they are fully tripartite, the 

 lateral segments being free and cuneate at the base. Occasionally a 

 plant is found in which the segments on the underside are much reduced, 

 showing a closer passage to or from triangulum. 



8. A. viviparum. Hook. — Rootstock stout, erect, densely clothed with 

 large blackish- brown scales ; stipites caespitose, 4-6 in. 1., erect-spreading, 

 strong, clothed at the base like, the rootstock, above fibrillose or naked ; 

 fronds rigid, lanceolate, or oblong lanceolate spreading, bi-pinnate, 

 tapering at the apex to the blunt viviparous summit ; pinnae spreading, 

 very numerous, acute, oblong-lanceolate, 2-3 in. 1. ^-f in. br., fully 

 pinnate within, the outer part pinnatifid ; segments close, rather 

 imbricating ovate, mucronate, the interior one on the superior side 

 enlarged, more apart and free than the rest, 4-6 li. 1. 2-3. li. w. their 

 margins even ; rachis strong deciduously fibrillose ; sori copious, biserial. 

 — PolysticltHin viviparum, Fee. Mem. p. 21. Tab.3. 



a. var. Fronds exactly similar, but pinnae only serrate or in- 

 ciso-serrate, the auricled base on the upper side sometimes separated 



