2 QQPBLAHD. 



KEY TO THE FAMILIES OF F1LICALES. 



Sporangium derived from a group of cells, wall more than 1 cell thick (EUSPOB- 



ANOIATAE) . 



Sporangia solitary, marginal on reduced segments 1. Ophioglossaceac 



Sporangia in sori, dorsal, on normal fronds 2. Marattiaccae 



Sporangium derived from a single cell; wall 1 cell thick (Leptospokangiatae) . 

 Spores of two kinds; aquatic plants (Kydropteiudixeae) . 



Leaves cruciform .3. Marsilcaceac 



Leaves not cruciform, plants floating 4. Salviniaceac 



Spores of one kind, mostly terrestrial (Eufilicineae) . 

 Leaves with the usual leaf tissues. 



Sporangium opening by a longitudinal alit. 



Annulus rudimentary 5. Osmundaccac 



Annulus subapical 6. Schizacaceac 



Annulus medial 7. Glcicheniaccac 



Sporangium opening by a more or less transverse slit. 

 Annulus oblique. 



Aquatic 8. Parkeriaceac 



Not aquatic, rhizome creeping 9. Matoniaceae 



Not aquatic, caudex erect, mostly tree ferns 10. Cyathcaecac 



Annulus longitudinal, incomplete 12. Polypodiaceac 



Leaves without stomata, usually without parenchyma.. 11. Hynienophyllaccae 



artificial key. 



Aquatic, leaves cruciform Marsilca, p. 12 



Aquatic, leaves simple, floating plants. 



Midrib present, but no veinlets Asolla, p. 14 



Veinlets present Salvinia, p. 14 



Aquatic, leaves pinnately compound.... Cera f opf en's, p- 20 



Terrestrial, stipules present Makattiace.*:, p. 8 



Terrestrial, stipules wanting. 



Frond forked into a sterile segment and a fertile one arising from it or below it. 



OPHIOGLOSSACE/E, p. 3 



Frond not forked into a sterile and a fertile segment. 



Leaves mostly very thin, sori terminal, inclosed by two equal thin valves 



( Hymenophyllace.e ) . 

 Leaves mostly thicker, sori not inclosed by two equal thin valves. 



llachis scandent, monopodial (dichotomous) Lyyodimn, p. 17 



Frond grass- or rush-like, digitate or dichotomous at top Schizaea, p. 20 



Fronds monopodial, pendent Phanerosorus, p. 28 



Frond* not monopodial, nor grass-like with digitate or dichotomous apex. 



Frond fan-shaped, with pinnate divisions Matonia, p. 27 



Frond not fan-shapped with pinnate divisions. 



Ultimate divisions pinnate, frond equally dichotomous below these. 



Cllricliciiid. ]). 22 

 Frond not dichotomous and then pinnate. 



Sporangia large, opening by a slit across the apex Osmunda, p. 15 



Sporangia not opening by a slit across the apex. 



Tree-ferns with oblique annulus (yatiikace.e, p. 28 



Not tree-ferns with oblique annulus. 



Annulus oblique, frond at least tripinnate Balantium, p. 61 



Annuls not oblique, or frond hut once pinnate (Poltpodiaoeje). 



