IHE VEGETATION OF JHE JUAN FERNANDEZ ISLANDS 847 



in its mode of occurrence this remarkable species difters from Robinsoiiia, from which 

 I segregated it {2J). It is very rare and grows on the low hills and ridges below the 

 forest at 300 — 3 50 m above sea-level, ranging from Puerto Frances to Pangal. The 

 habit is the same as in Robinsonia, but more straggling (PI. 68: 2). According to 

 Johow it grows to a height of 3 — 5 m, but we found no specimens surpassing 2 m. 

 Bark about i mm thick, gray with brown leaf scars; wood cylinder i mm thick, 

 filled with a dense, farinaceous, yellowish pith. On Dec. 13, when we came across 

 Syuipliyochaeia for the first time, the male plants were long past flowering and 

 the female on the decline; there was no sign of any gemmae which, in Robinsonia, 

 are well advanced during the flowering season. Fig. 12 f shows a fruiting branch 

 at the end of March, when the involucre was bursting open and the achenes ripe. 

 The branch is leafless but bears 3 innovations (II), one very much smaller 

 than the other two, but they are not placed in the axils at the base of the ped- 

 uncle but toward the base of the branch. They cannot very well reach maturity 

 and produce an inflorescence already next spring, but will need at least a year 

 and a half before this happens. On PI. 68: 2 several long, vegetative shoots are 

 seen, very likely 2 — 3 years old. 



Seeds sown 22.3. 1918 gave 4 seedlings in the beginning of May, and i.io the 

 tallest plant was 50 cm high, but unfortunately all died during the winter. 



Rheti7wdendron BerteriiiJ^cne) Hemsl., "Resino hembra" (female r.), "incensio". 

 Endemic in the elevated central part of Masatierra, in open brushwood and forest 

 along the ridges, rarely observed below 500 m but found down to 400 m on the 

 south side, where it extends west to Cerro Chumacera. Also on the summit of 

 El Yunque, where unusually large-leaved plants occur (Skottsb. 14. 159, fig. 4). 

 Johow states p. 55 that Rhetinodendron often grows as an epiphyte on Dicksonia, 

 and on p. 250 that "a veces se encuentra tambien en el suelo pero con preferencia, 

 i no solamente en su primera edad sino tambien como arbol crecido, habita los 

 troncos de la Dicksonia berteroana . . ."; a photograph taken in the forest on the 

 south side of Portezuelo (PI. XVI) shows a tall Dicksonia, and the explanation p. 287 

 tells that a specimen of Rheti7iodendron grows on the base of the fern. The long- 

 stemmed supposed epiphyte is distinctly seen, but unfortunately the lower portion 

 of the trunk is completely hidden; still we have no reason to doubt the correctness 

 of Johow's statement. But was it RJietinodendronr There is little difference, when 

 seen from a distance, between this and Robinsonia evenia, which, as we have seen 

 above, is a regular epiphyte, but Johow tells (p. 60) that he failed to find this 

 species. On the photograph is a much smaller plant, probably of the same kind, 

 attached to the fern trunk a little below the top, but not referred to by Johow. 

 His statements made us pay careful attention to the question of epiphytism; we 

 came across 2 seedlings on the trunk of TJiyrsopteris, but were unable to find 

 an adult, epiphytic specimen. Neger makes the following curious statement (1. c. 

 p. 458): "Auf der Robinson-Insel Juan Fernandez siedelt sich die sonst terrestrisch 

 lebende baumartige Komposite Retinodendron Berterii nur auf dem Baumfarn 

 Dicksonia Berteroana an" — but R/ietijiodendron is only found on Masatierra. 



Height according to Johow 2 — 4 m, but trees 5 m tall were seen more than 



