THE VEGETATION OF THE JUAN FERNANDEZ ISLANDS 



883 



Fig. 30. Hymenophyllum fucifontie. large plant in the forest of \'illagra, Masatierra, c. 550 m 



above sea-level. — Photo 10 i 191". 



not as large, is H. caudiculatu)>i Mart, which is much rarer on Masatierra than on 



Masafuera. 



Trichomanes exsectum Kze is the only species of this genus inhabiting both 



islands; a fine carpet is seen on PI. 83. The small T. higae C. Chr. (p. 4, fig. 2, 



endemic) and T. philippianuDi Sturm (p. 3, fig. i) have only been recorded from 



Masatierra. Serpyllopsis caespitosa, a rather variable plant, is represented in the 



islands by var. fer)iandeziana C. Chr. et Skottsb. 



Many filmy ferns are terrestrial and epiphytic; such is the case with Hymeno- 

 glossum, Hymejwphyllum cuneation, falkhmdicum,ferrugineum,peclinatum.plkaUnn 

 and rugosum. Trichomanes exsectum and Serpyllopsis. The latter is nearly ahva\-s 

 epiphytic, on Drimys and Dicksojiia, and the trunks of tree-ferns seem to be pre- 

 ferred by most species. TricJiomanes philippimtum, endemic on Masatierra, has 

 not been found growing on the ground but exclusively on the trunks of Dick- 

 sonia herteroami. and BlecJmum cycadifoliion. 



In his "Biologic der Pflanzen ', p. 220, Xeger wrote: "In extremer Ausbildung 

 finden wir 'hygrophile Struktur' bei den stets von dampfgesattigter Luft umge- 

 benen Hautfarnen [Hymenophyllum), welche in tiefem Waldschatten der ewig 

 feuchten tropischen und subtropischen Regenwalder gedeihen. Xaturlich sind 

 diese Gewachse im hochsten Grad emfindlich gegen jede auch nur voriiberge- 

 hende Austrocknung." With these words the author wanted to emphasize that 

 the filmy ferns are unable to stand desiccation, even if of short duration. On 



