THE PTERIDOPIIVTA OF THE JUAN FERNANDEZ ISLANDS 33 



Masatierra: In all the valleys from Pto Frances to Juanango (nos. 59, 

 59 b, 57 



Santa Clara: J' 1H1 »W. 



Masafuera: Common along the shore from B. Tolten round the E. and 



S. coasts to Q. Loberia, especially under overhanging rocks (no. 446); also in 



the forest (no. 518) and in the alpine heath, to 1400 in. 



All specimens examined belong to the genuine ./. chilense, characterized 

 by perfectly glabrous fronds. JOHOW described and figured three forms. Of 

 these, the first (fig. 5 a) is a robust one, with a strong stipe, and the third a 

 smaller one (fig. 5 c) with a slender stipe; surely they represent two local 

 forms differing from humidity and shade. Both are represented in our collection. 



The second variety ofJOHOW (fig. 5 b) is remarkable by the pinnae being 

 more or less striped with white, forming white sections of tissue without chloro- 

 phyll. Suggesting that they were due to some pathologic cause, Dr. H. E. 

 PETERSEN on our request made microtome sections- through such leaves and 

 found that the cells of the white parenchyma were filled with an entangled 

 mass of hyphae of a parasitic fungus that destroys the chlorophyll. 



Area of distribution: Peru to Patagonia, Falkland Islands; Juan Fer- 

 nandez. 



Pteris L. 



37. P. chilensis Desv. Perl. Mag. 5: 325 (181 1); Hook. Sp. Fil. 2: 176 

 tab. 120 A; Hemsl. yo; C. Chr. Ind. 594; nan Johow 1893 fig. 7 nee 1896: 

 156, saltern pro parte. — Syn. P. tenera Klf. 1824; Gay 6: 488 {non Bertero); 

 P. femandesiana Phil. Linnaea 29: 105 (1857), t. spec. orig. Herb. Mus. Nac. 

 Santiago! 



In humid forests, on soil rich in humus; not observed at a greater altitude 

 than 500 m in Masatierra. (Fertile Dec. — April.) 



Masatierra, not uncommon in the central part: C. Centinela, c. 400 m 

 (no. 609); V. Anson, lower slopes of La Damajuana, 345 m (no. 216); V. Co- 

 lonial, at the road to Portezuelo, in the maqui-thickets, 200 m (no. 566); Q. del 

 Monte Maderugo, c. 500 m (no. 337); C. Salsipuedes, forest patch c. 400 m; 

 Pto Ingles, on the central ridge (no. 324); south side of the island, slope of 

 Co Chumacera (no. 252). 



Masafuera: in the forest of the Sanchez plain, 515 m (no. 401); Q. de 

 las Chozas, in the forest (no. 544); Q. de las Casas, under a large stone in the 

 outer section of the gorge, rare. 



The present species is nearly related to the South Brazilian P. leptopliylla 

 S\v., but still very distinct. Its rhizome is short creeping, rather stout, densely- 

 covered with dark brown, rigid, lanceolate scales, as is the larger part of the 

 stipes, which rise close together. P. fernandesiana Phil, cannot stand even as 

 a variety; the type of P. chilensis is quadripinnatifid, but some specimens, 

 growing in deep shade, are barely tripinnate at base, and the lamina more open 

 and thin, and they represent the true P. fernandeziana. 



JOHOW's P. chilensis, as proved by his figures, description and specimens, 



3 — 2020B. The Nat. Hist, of Juan Fernandez and Easter Isl. Vol. II. 



