M. E. Boissier on new Facts in Botanical Geography. 465 
all the tropical regions, both of the Old and New World. Only 
a few species inhabit the temperate regions of the northern he- 
misphere, and among these I may cite the D. villosa of the 
United States, and in Japan the D. Batatas, recently introduced 
among us as an alimentary root under the name of the Japanese 
Yam. Hitherto no Huropean species of Dioscorea has been 
known, until, a few years ago, it was reported that M. Bubami, 
an Italian botanist, had found one on the Pyrenees. As the 
details of this discovery were nowhere published, it was sup- 
posed that there might be some error of determination; it was 
thought that this could only be a Zamus, a European genus of 
the same family, very distinct from Dioscorea in having its fruit 
a berry and not a capsule, but of which the very similar aspect 
may easily, when it is only in flower, lead to its being con- 
founded with the latter genus. This, however, was by no means 
the case; I have just received from M. Bordére, of Gédre, in 
the Hautes-Pyrénées, some specimens of the plant in question, 
which, from its tuberous root and its membranous 3-celled cap- 
sules, undoubtedly forms part of the genus Dioscorea. Dioscorea 
pyrenaica, Bub., is an alpine plant which grows upon the ealca- 
reous débris on the southern slope of the Col de Gavarnie ; 
and, what is very remarkable, by its dwarfed and flexuous and 
not climbing stems it exactly recalls. (although specifically 
distinct) other alpine Dioscoree, such as D. nana and D. mul- 
tinervis, which must be sought in the Andes of Chili and Peru 
and upon the mountains of Mexico. 
A second curious fact is the discovery, also dating a few years 
back, of a Pelargonium among the mountains of the Kast. The 
genus Pelargonium, which includes the so-called Geraniums .- 
cultivated in our conservatories, is characterized, in the family 
of which it forms a part, by the nectariferous tube, which de- 
scends from the calyx and becomes united throughout its length 
with the peduncle ; it has hitherto been regarded as exclusively 
indigenous in the southern hemisphere, most of its species in- 
habiting the Cape of Good Hope, and a few Australia. But M. 
Kotschy brought from the Taurus in Cilicia a beautiful plant 
belonging undoubtedly to this genus; and it has since been 
found along the whole of the same chain, from Pamphylia to 
Armenia. Like some other species from the Cape, Pelargonium 
Endlicherianum has the inferior petals very small and nearly 
aborted; the upper ones, which are very large and of a fine 
purple, render it an ornamental plant, which is the more valua- 
ble as it can bear our winters. 
I now pass to the third species that I have to mention here. 
It is already many years since Bertero collected in Chili a para- 
sitic plant growing in great abundance upon the branches of an 
Ann. & Mag. N. Hist. Ser.3. Vol. xvii. 30 
