DUSEN : THE VEGETATION OF WESTERN PATAGONIA. 27 



stand in such dense order of growth as its European cousin, Fagus syl- 

 vatica L. A solitary specimen of Nothofagus pumilio may be occasionally 

 encountered. 



The light in these forests is stronger than in the beech forests of Europe, 

 not only by reason of the trees not standing very close together, but also 

 because, as a rule, one or other of their main branches is withered. Evi- 

 dently, this cannot be due to fire, nor does it appear to be caused by the 

 ravages of parasites in excessive numbers, whether species of Myzodendron 

 or parasitical fungi ; the reason is unknown. 



The bright light prevailing in these forests and the fertility of the soil 

 sufficiently explain their rich undergrowth, so extremely different from 

 that of the beech forests of northern Europe, which also grow on humus. 

 The difference may be illustrated by a few comparisons. Among other 

 features of the beech forests of northern Europe are the following : the 

 undergrowth is very sparse and poor in species, the ground being nearly 

 bare of vegetation and strewn with fallen leaves and involucres ; shrubs 

 are wanting, while spring flowers are common, likewise plants with under- 

 ground stems, not rarely consisting of a creeping rhizome ; the great 

 majority of plants are perennial ; saprophytic plants occur ; mosses and 

 lichens are almost entirely wanting. In nearly all these respects the 

 beech forests of the upper Aysen valley are different. A vegetation of 

 shrubs occurs, though it is but poorly developed ; the flora is not particu- 

 larly rich in species, but the vegetation is dense ; the ground is nowhere 

 bare of plants ; of spring flowers there are none, except some species of 

 Berberis and Ribes, which should perhaps be counted as such ; most spe- 

 cies flower in summer and the beginning of autumn ; bulbous and sapro- 

 phytic plants are wanting ; the number of annual and perennial species is 

 about the same as in Europe ; mosses do not grow on the ground, but 

 sometimes plentifully on the tree-trunks ; the vegetation of lichens, some- 

 times abundant, consists of only a single species, Letharia poeppigii (Nees 

 et Plot), other species being few and rare. 



Of plants composing the undergrowth, some are conspicuous by their 

 occurrence in large masses, such as Galium aparine, extremely common 

 and forming quite a network on the top of the other vegetation ; Vicia 

 daropskyana, plentiful ; Mutisia retusa, sometimes abundant ; Acczna oval- 

 ifolia, common, even abundant here and there ; Osmorhiza berterii, plen- 

 tiful ; Calceolaria darwinii, Uncinia phleoides and Carex filiformis subsp. 



