NO. 1867 AMERICAN FERNS — CIIRISTENSEN 375 



DRYOPTERIS OPPOSITA (Vahl) Urban. 



(Revision 288, No. 25, Fig. 15.) 



Typical Form : Rather small, the leaf narrowed downwards 

 through a long row of gradually reduced pinnae. Segments a little 

 oblique, obtuse or with rounded apex, short, with 4 to 6 pairs of 

 veins, the basal ones not much prolonged. 



Dominica : Laudat, F. E. Lloyd 26. 



St. KiTTs : Wingfield Estate, forest ravine, Brilton and Cowell 446. 

 St. Vincent: Ad Calvary, in locis umbrosis, Eggcrs 6732. 

 Grenada : Sherring. 



Tobago : Ad Cremorin River, in sylvestribus humidis, Eggcrs 5850. 

 Trinidad : Without locality, Fendlcr 65 ; Jenrnan. 



Porto Rico : Clay bank, road from Gnayama to Cayey, Undcnvood mid 

 Griggs 432. Cayey, ad rupes in flumine Morillos, Sintenis 2281. 



I have seen no specimens exactly agreeing with this typical form 

 either from the larger islands or from the continent. In Central 

 America it apparently does not occur. The specimens in my "Re- 

 vision" referred to D. opposita I now believe to belong to D. pana- 

 mensis. 



FORMS INTERMEDIATE BETWEEN D. OPPOSITA AND D. 



PANAMENSIS 



Jamaica: Maxon 802, 821, 996 (=Underzcood 2130), 1000 (= Und. 2135), 



1528 (=Und. 2601) ; Hart 128. 

 Mexico : Without locality, Kerber 437. 

 Florida : Miry hammock near Fort Meade, Polk Co., /. Donncll Smith, 



March, 1880. 



These intermediate forms resemble in size and fewer reduced 

 pinnee D. panamensis, in their opposite pinnae and short segments 

 D. opposita; in general habit most of them agree very well with D. 

 panamensis, to which species I am inclined to refer them. The 

 specimen from Mexico belongs to the form named by Fournier^ 

 Aspidhim exsudans var. myriocarpum; it is a form with linear 

 pinnae and short segments. The Florida plant is Aspidiiini conter- 

 miniim var. strigosum of North American authors, believed to be 

 identical with A. strigosum Fee from Guadeloupe, which, however, 

 is true opposita. Jenman (as shown in letters to Capt. Donnell 

 Smith) considered it to be D. Sprengelii, which indicates that Jen- 

 man quite misunderstood D. Sprengelii, as also his descriptions 

 under that name show. The Florida fern is to me not essentiallv 



•Mex. PL i: 98. 1872. 



