nee 
X, 
2. 
The Species of the Genus Larix. 105 
V. Summary. 
In the present paper the areas of distribution of the 
various species of larch are dealt with in detail, but 
only as far as the distribution concerns the wild-growing 
- plants; the cultivation of the larches, which in many 
regions is of rather considerable economic interest, has 
mostly been omitted. 
The authors recognise 10 species of larch and three 
geographical varieties. According to the international 
rules of nomenclature, the following names are valid: 
L. Griffithiana, L. Mastersiana, L. Potanini, L. occidentalis, 
and L. Lyallii, which five species constitute a natural 
sub-genus, characterised by the bracts of the cone being 
longer than, and reaching out of, the cone scales. All 
these species have restricted areas of distribution, being 
mountain trees from the great mountain regions of 
western N. America and south-eastern Asia respectively. 
Of these, only L. occidentalis has any considerable 
economic value, but none of them have hitherto been 
taken into culture on a large scale. 
3. The five other species are L. Kaempferi (L. leptolepis) 
L. Gmelini (L. dahurica) with the varieties olgensis and 
Principis Rupprechtii, L. sibirica, L. decidua (L. europaea) 
and L. laricina (L. americana). Of these, L. Kaempferi 
has a small area of occurrence on Hondo, Japan, while 
L. decidua has a medium-sized area. L. Gmelini, L. sibi- 
rica, and L. laricina, on the other hand, have very large 
areas, the last inhabiting the northern temperate and 
sub-arctic zones of N. America from Newfoundland to 
Alaska. L. Gmelini and L. sibirica divide Eurasia between 
them, L. Gmelini being found in Eastern Asia, and as 
