510 
fc'ILICES. 
26. ACROSTICHCJM, Linn. 
Capsules stalked, splitting transversely, with an incomplete vertical 
ring. Sori spread in a regular stratum over the whole surface of the 
frond or of the upper pinnae, without any involucre. — Ferns of very 
various texture, cutting and veining, the fertile fronds or segments 
often different from the barren in shape and size. Distbib. Both 
hemispheres, principally within the tropics. Species 140. 
Subgenus Elaphoglossum. Veins free. Fronds simple. 
Sterile frond naked. 
Marginal scales none. 
Sterile frond linear, in. broad 1. A. lineare. 
Sterile frond lanceolate or oblong-lanceolate. 
Sterile frond 4-6 in. long 2. A. conforme. 
Sterile frond 6-12 in. long. 
Basal scales lanceolate 3. A. latifolium. 
Basal scales linear-subulate 4. A. Sieberi. 
Marginal scales few 5. A. hybridum 
Sterile frond obscurely minutely scaly. 
Basal scales linear- subulate, dark brown . . . . . 6. A. viscosum. 
Basal scales lanceolate, light brown 7. A. Boivini. 
Sterile frond densely conspicuously scaly. 
Sterile frond oblong or obovate- oblong, 1-2 in. long . 8. A. spathulatum. 
Sterile frond lanceolate, 4-6 in. long 9. A. squamosum. 
Sterile frond lanceolate, 1-H ft. long 10. A. tomentosum. 
Subgenus Stenochl(ena. Veins free. Fronds compound. Fertile 
frond with narrow linear segments. 
Fertile frond simply pinnate 11. A. sorbifolium. 
Fertile frond bipinnate 12. A. tenuifolium. 
Sub genus GIymnoptebis. Veins anastomosing, unequal, the main 
ones distinct to the edge. Fertile frond soriferous all over the under 
surface. 
Frond simply pinnate 13. A. punctatum. 
Frond bipinnatifid 14. A. repandum. 
Subgenus Chbysodium. Veins anastomosing, equal. Fertile frond 
soriferous all over the upper pinnae. 
The only species 15. A. aureum. 
Subgenus Hymenolepis. Veins anastomosing. Frond simple, 
soriferous only on the contracted tip. 
The only species 16. A. spicatum. 
1. A. simplex, Sw. ; Hook, and B^ker, Syn. Ml. 400; var. A. 
mabtinicense, Desv. Rootstock woody, short-creeping ; scales 
minute, brown, lanceolate. Sterile frond linear, 6-8 in. long, f-J in. 
broad, naked, rigidly coriaceous, obtuse or subacute, narrowed very 
