—24— 



123- Nephrodium spinulosum dilatatum (Hoffm.) 

 Broad Wood Fern. Tolerably common ; in. 

 rocky soil. An upland or mountain form found 

 at sea-level in the far north, but limited to the 

 mountain tops in the southern part of its range. 

 — Dryopteris spinnlosa dilatata (Hoffm.) ; Aspid- 

 ium spinulosum dilatatum (Hoffm.) 



124. Nephrodium stipulare (Willd.). Rare. Southern 



Florida. Regarded by many as a form of N. 

 patens and more properly named Nephrodium 

 patens stipulare* Has the same range as N. 

 patens. — Dryopteris stipularis (Willd.). 



125. Nephrodium thelypteris (L.). Marsh Fern. 



Abundant; in swamps and wet woods. North 

 America east of the Rocky Mountains in suita- 

 ble situations; also Europe, Asia, Africa and 

 Australia. The form Pufferae A. A. Eaton is a 

 forking form from Massachusetts. — Dryopteris 

 thelypteris (L.); Aspidium thelypteris (L.). 



126. Nephrodium unitum glabrum (Mett.). Not rare; 



in open swamps. Florida and Texas; also in 

 the West Indies and nearly throughout the 

 world in the tropics. This has recently been 

 named Dryopteris gongy lodes (Schkuhr), but 

 is more properly Nephrodium gongylodes 

 (Schkuhr). — Dryopteris unit a glabra (Mett.); 

 Aspidium unitum glabrum (Mett.). 



PTERIDOGRAPHIA 



Marsilia Leaves and Light. — The curious fact that 

 Marsilia, like the clover and oxalis, closes its leaves at 

 night, has long been known, but Robert F. Griggs has 

 recently noted what appears to be a new motion of the 

 leaves to enable them to face the sun. Thus far the habit 

 has been noticed in but one species, M. vestita, but it is 



