THE PTERIDOPHYTA OI THE JUAN FERNANDEZ ISLANDS 7 



Ifasafuera : Q. de las Casas, humid moss mats in the inner can 

 scarce (no. 4751; C. del Barril, in moss on rocks, c. 750 m (no. 407). — New 

 for this island. The specimens are small and sterile. 



In restoring the genus Hymenoglossum we follow van DEN BOSCH, the 

 monographer of the family, contrary to all other pteridologists. Our reasons 

 for doing so are not only the unique habit of the plant, but are based upon a 

 very essential character, overlooked by PRESL and all later authors. The 

 margins of the frond, not the sterile parts alone, but also the valves of the 

 indusium, are bordered by a thick ebeneous line. The veins terminate in the 

 parenchyma within this line. 



Area of distribution: South Chile, Valdivia to Chiloe and Western 

 Patagonia to 49/; Juan Fernandez. 



Hymeiiophyllum Sm. 



6. II. cuneatum Kze, Anal. 50 (1837); C. Chr. Ind. 359, Arkiv for Bot. 



10: 21 (iqio). — Syn. H. rarum auctt. quoad plant, amer.; Hemsl. 6$; Johow 



42 f. 30, 1896: 171. H. polyanthos auctt. quoad plant, fernand.; Hemsl. 



67; Johow 1S93: 42 (pro pa te: non f. 29), 1S96: 172 (pro parte ?). H. dichoto- 



mum. Johow 1893: 44 ^pro parte:) f. 2;, 1896: 173 (pro parte:). 



Fig- 3- 



Probably fertile at any time of the year. 



Under this name whe unite all the smaller glabrous Hymenophylla of the 

 islands, being convinced that they all belong to one species, although the ex- 

 treme forms look very different. All forms agree in cellular structure and in 

 shape of the indusium, which is broad, fiat with a broad subtruncate or 

 broadly cuneate base and with rounded or sometimes subacute valves. The 

 indusium varies, as our figures show, in the same degree in the largest and 

 smallest forms. 



Kunze described the stipe as unwinged. We tir.d among the very ex- 

 tensive material several individuals which correspond perfectly to his description 

 (no. 396); they have ovate or subdeltoid, middle-sized, yellowish-green fronds 

 with wingless stipe and broad, semiorbicular indusia. Other plants agree with 

 these in all respects but have the stipe winged to the base (no. 1143). We 

 suppose that these are younger plants, while fronds without wings are older, 

 having lost the wings. Large or small fronds occur with or without a winged 

 stipe. If no. 396 is considered to be a typical, middle-sized form, the other 

 specimens may be arranged as follows. 



1) Large plants, over 15 cm long inch stipes, more decompound, with 

 narrower, ovate-lanceolate lamina, often of a deeper green (no. 285). Such 

 plants have been referred to H. polyantlios Sw. by all authors, and probably 

 also the more typical form was brought to this species by some. It is very 

 difficult to find a single constant character by which the larger forms may be 

 known from the variable H. polyanthos: the lobes are generally broader, the 



