POLYPODIACEiE. HQ 



19. Pteris semihastata, Wallich. 



..48. 

 Hab. Singapore : in open situations. 



Pteris semihastata, Wallich, ex Agardh, Gen. Pterid. p. 



This seems to hold an intermediate position between the P. escu- 

 lenta of Forster and P. aquilina of Linnaeus; differing from the 

 former in the almost total absence of the lobule between the segments, 

 which are much shorter, and villous on the under surface. In the 

 latter particular, as also in the habit and form of the divisions of the 

 frond, it approaches very nearly indeed to states of P. aquilina; from 

 which it appears to differ only in the decurrent and semiauriculate 

 tendency of the base of its segments. 



tt Segmentls absque lobulo interposito. 



20. Pteris aquilina, Linn. 



Pteris aquilina, Linn. ; Willd. Spec. PI. 5, p. 402; Agardh, Gen. Pterid. p. 49; 

 Hook. EL Bor. Amer. 2, p. 263. 



Var. /3. frondihus subtus plus minusve tomentosis. 



Pteris decomposita, Gaud. Bot. Freyc. Voy. p. 393; Agardh, Gen. Pterid. p. 53. 

 P. lanuginosa, Hook. & Arn. Bot. Beech. Voy. p. 405. 



Hab. Island of Madeira. Vicinity of Cape Town, Cape of Good 

 Hope. Var. /3. Northwest Coast of America, from Puget Sound, 

 Oregon, to San Francisco, California. Sandwich Islands ; as high as 

 8,000 feet above the level of the ocean. 



The P. decomposita of Gaudichaud, as characterized by him and 

 retained by Agardh as a species, we cannot regard as anything more 

 than a mere variety of P. aquilina, with fronds more or less tomen- 

 tose on the under surface, and varying in this respect in proportion 

 to the elevation at which the specimens were obtained; as those 



