The Species of the Genus Larix. 15 
DALLIMORE & Jackson: Handb. Conif. 1923, p. 292. — REHDER: 
Man. Trees and Shrubs, 1927, p. 51. — 
In the west of China, two species of larch are to be 
found, L. Potanini and L. Mastersiana, of which the former 
is the commonest, the later having only a very limited 
area of distribution. 
L. Mastersiana occurs only inside the zone of distribu- 
tion of L. Potanini: all in all, it is only known from three 
localities, lying north and south in the mountains west of 
the Min river. In 1908—1910, when WILson discovered it, 
it was quite common in this restricted area, and being 
greatly in demand on account of its valuable timber, has 
decreased rapidly, but the inaccessability of its habitat 
prevents its extermination for the present. 
It is a small tree, only some 10—20 nı. in height. Its 
branches of the 2nd order are pendulous, although not 
so strongly as in the case of L. Potanini or L. Griffithiana, 
which generally resemble one another in this particular. 
The one-year’s shoots are smooth, or very slightly pilose; 
the bark has a fresh, yellowish-brown colour. The leaves 
are placed in bundles of up to forty in number on the dwarf 
shoots, and are 1,2—3,5 cms. in length, light green in 
colour, with two light bands of stomata on the under-side. 
They present no appreciable difference from those of L. Po- 
tanini, being distinctly keeled on the under-side in simi- 
larity with the latter, the keel being less distinct on the 
upper-side, and only really apparent at the base, The 3—4 
cms. long cone is brown, the bracts, which are longer 
than the cone-scales, are red and recurved. The length is 
described as being from 3—4 cms., but a cone from 
an original specimen lying before us (Wırson No. 906) 
has nevertheless attained a length of 4,5 cms. 
