nar 
think, that Polystichopsis must be considered a natural genus between Dryopteris 
and Polystichum. 
The American species of this subgenus fall into two groups: 
1. Group of D. pubescens. Smaller species, less divided and less distinctly 
anadromous; long, soft hairs often numerous. Indusia small, early deciduous, often 
not found. (Species 353—356). To this group the name Polystichopsis was applied 
by J. Smirn, but be consociated with D. pubescens some species (D. protensa and 
its allies), which are widely different. His distinguishing characters were the 
creeping rhizome and the decompound lamina. It is, however, justified to use his 
name in another sense, also including in the subgenus the second group, the species 
of which J. Smirn referred to his Polystichum § Tectaria (sic!). 
2. Group of D. decomposita. Decompound, generally coriaceous species with 
anadromous venation in all divisions, most often quite glabrous or slightly pubes- 
cent. Indusia large, coriaceous, often rotundato-reniform. 
It is quite possible that the well-known Polystichum adiantiforme (Forst.) J. Sm. 
should be referred to the second group. I cannot for the present decide whether 
such a treatment would be a natural one, and I have, therefore, in this work ex- 
cluded the said species. If a minute and comparative examination of all its charac- 
ters should prove that it forms a natural genus with Polystichopsis, this must bear 
the name Rumohra Raddi. 
A derivate of Polystichopsis of proportionally recent origin is Maxonia C. Chr. 
Smiths. Muse. Coll. 66°. 1916, which again leads to the more specialized genus 
Polybotrya with the species P. osmundacea H. B. W.; most other or all of the species. 
in Index Filicum referred to Polybotrya are to be excluded from that genus. 
Key to the Species. 
1. Lamina, at least on rachises beneath, with long, soft, pluri-cellular hairs. 2 
— Lamina without long hairs. 5 
2. Long hairs scattered over the surfaces, most numerous on rachises and veins 
beneath. Smaller West-Indian species: lamina 10—30 cm long 3 
— Long hairs confined to the rachises beneath; lamina 50—80 cm n high, coriaceous. 
_ Indusium large. 356. D. ochropteroides (Bak.) C. Chr. 
3B. Bipinnate-tripinnatifid. Indusium very early falling, thin, rarely found. 4. 
rae oe e-quadnpinnatifid. Indusium persistent. Lower side of basal pinne pro- 
_.. duced. 355. D. lurida (Jenm.) Und. et Maxon. 
4. Lamina bright-green, softly to firmly herbaceous. Secondary pinne of middle 
_ pinne 5—7 mm broad, 8—12 mm long; lower side of basal pinne not or a 
little produced only. 352. D. pubescens (L.) O. Ktze. 
hosp ‘Lamina dark-green, chartaceous. Secondary pinne of middle pinne 10—15 mm 
