Asplenium. ] 
FILICES. 
485 
Frond membranous ; rachis naked 15. A. bulbiferum. 
Teeth, of segments small 16. A. cuneatum. 
Ultimate segments very narrow, linear or ligulate. 
Segments ligulate, obtuse 17. A. borbonicum. 
Segments linear, acute 18. A. viviparum. 
Subgenus II. Diplazium. Veins free. Some of the sori double, 
placed back to back. 
Frond simply pinnate 19. A. sylvaticum. 
Frond tripinnatifid. 
Rachises unarmed 20. A. arborescens. 
Rachises prickly 21. A. sechellarum. 
Subgenus III. Thamnopteris. Veins uniting in an arch just 
within the edge. 
The only species 22. A. Nidus. 
Subgenus IV. Antsogcxntum. Veins uniting. Some of the son 
double. 
The only species 23. A. proliferum. 
1. A. Sandersoni, HooJc.; Hook, and Baker , Syn. Fil. 196. Rootstock 
erect ; scales minute, brown, lanceolate. Stipes tufted, green, naked, 
1-2 in. long. Frond lanceolate, membranous, glabrous, simply pinnate, 
4-6 in. long, f- 1 in. broad, often rooting at the tip. Pinnae 12-20 on 
a side, deltoid or square, nearly sessile, cut away in a straight line on 
the inner and lower sides, deeply crenated on the upper and outer. 
Veins few, flabellate, one running up the centre of each lobe. Sori 
oblong, medial on the veins. Involucre pale, ciliated. 
Mauritius, between Grand Bassin and Petrin, Sir H . Barkltj ! Also Madagascar, 
Natal, and Tropical Africa. 
2. A- resectum, Smiths Hook, and Baker, Syn. Fil. 210. Rootstock 
slender, wide-creeping ; scales very minute. Stipes \ ft. long, distant, 
slender, naked, bright brown. Frond lanceolate, bright green, membra- 
nous, simply pinnate, \-l foot long, 2-4 in. broad; rachis quite naked. 
Pinnae numerous, nearly sessile, rhomboid, 1-2 in. long, in. broad, 
faintly or deeply toothed down the upper and outer edges, parallel with 
the rachis on the upper side at the base, truncate at a right angle with 
the rachis on the lower side. Veins fine, distinct, very oblique. Sori 
medial on the veins, T V~ g- in. long. Involucre membranous, glabrous. 
Mauritius and Seychelles, in damp ravines. Spread through the tropics of the 
Old World. 
3. A. longissimum, Blume ; Hook, and Baker , Syn. Fil. 199. Root- 
stock erect; scales linear, small, bright brown. Stipes naked, reaching 
a length of nearly a foot. Frond 1-3 feet long, 2-4 in. broad at the 
