THE VEGETATION OK THE JUAN FERNANDEZ ISLANDS 



Tabic XX\\ Po/y/'odiuiH ijilcruicdiuni. \\'ei<^ht in ^rams. 



^ Frond on branchlet dead since several days, the one on the main rhizome still green and 

 turgescent. - Of all eleven fronds only the one on rhizome I still quite fresh. ^ Fronds 



beginning to droop. ^ Both fronds yellow and dead. = The single frond fading. * Frond 



dead. ' Oldest frond withered. * Also next oldest frond drooping. ' Youngest frond 



beginning to turn yellow. i" All fronds dead. " Fronds beginning to fade. ^^ Oldest 



frond dead. ^^ All fronds dead. 



forest and widely spread in smaller and more stunted forms in the barren country, 

 where it ranges west to Punta Larga and Santa Clara I., and it is just as common 

 on Masafuera. The shade-form is illustrated on PI. 83. Equally widespread, from 

 near sea level to the high mountains and extending west as far as Bahia Chu- 

 pones, is Polystichu)}i bertericniuui (Colla) C. Chr. with a wide-creeping rhizome 

 and fronds ^ 2 to i m high; in Masafuera it reaches the Alpine region, 1 300-1400 

 m. Histiopteris incisa (Thunb.) J. Sm. has the same large distribution as the for- 

 mer and is a characteristic fern of recently burnt areas. It is a stately fern, large 

 specimens attaining the height of man. Hypolepis rugostila (Labill.) J. Sm. (Skottsb. 

 ij. 369, fig. 4), also common, but less widespread, belongs to the lower region 

 in Masatierra and was not seen above the timber-line on Masafuera. Another 

 very common fern is Adiantuiu chilense Kaulf , found in the forest as well as on 

 the banks of streams and roads in company with Hypolepis, PolysticJiion, Blech- 

 nurn aiiriailatuui etc. It is one of the few species inhabiting the coast cliffs in 

 the three islands. The special seaside fern is Aspleuimn ohliqiumi Forst. (PI. '/'j: 2) 

 in its endemic, but not too well-marked variety cJwndropJiylluni (Bert. MS). Mett., 

 a succulent haloph\-te found in the three islands. The few stations where the 

 small, densely tomentose, xerophilous Pellaea cJiilensis Fee (endemic, both islands) 

 has been found are, with one exception, dry rocks of the coast. Another drought- 

 resistant fern is Gleichenia pedalis (Kaulf.) Spr., only found on Masatierra on the 

 mountain-spurs surrounding Bahia Cumberland. As this conspicuous species is 

 wanting in collections made before 1854, it is suspected to be a late arrival from 

 south Chile. 



Of the ferns inhabiting the humid forest and well-watered gulches three large 

 species are met with all through the wooded country in both islands, Blec/nnan 

 chilense (Kaulf.) Mett, Polysiichum vestitiwi (Forst.) Presl and Pteris berieroana 

 Ag., the last-mentioned endemic. Blechnum chilense is a social fern with fronds 

 50 — 70 cm long; it seems to prefer open glades and banks of streams, ranging 

 w^est to Cerro Chumacera and Bahia Chupones in Masatierra. In Masafuera it 

 also inhabits the Alpine region (Pis. 93, 112). Polysiichum vestitum \s r\ot uncom- 



