6 Nr. 2. C. H. OSTENFELD and C. SyRACH LARSEN: 
Key to the Species and Varieties of Larix. 
I. Bracts longer than the cone-scales. Leaves slightly 
or strongly keeled on both sides; the upper-side may, 
in exceptional cases, be without keel. 
A. Bracts reflexed. 
a) Bracts much longer than the cone-scales. 
The cone 5—11 cms. long..... 1. L. Griffithiana. 
b) Bracts only slightly longer than the cone- 
scales. The cone 3—5 cms. long. 2. L. Mastersiana. 
B. Bracts straight or slightly recurved. 
a) The cone long and narrow; length to breadth 
1,4—1,7; Bracts 0—2 mm.’ longer aia 
the cone-scales. Leaves deeply keeled on the 
under-side; slightly less keeled on the upper- 
side; 192 CS FONG ee ee ee 3. L. Potanini. 
b) The cone short and broad. Length to breadth 
1—1,5, leaves 2,5—4 cms. 
1. The leaves are more strongly keeled on 
the upper- and under-sides than in the 
case of any other species. The young 
shoots are particularly densely pilose. 
The cone - 3,5—5 cms. long: Brits 
SEAT SER MOLI AGG Se INC, CORTE 4. L. Lyallii. 
2. The leaves keeled on the under-side 
only. The young shoots at first somewhat 
pilose, finally smooth. The cone 2,5—3 cms. 
long. The bracts straight or slightly 
TECULYER. 1. ran eee: 1 5. L. occidentalis. 
II. Bracts shorter than the cone-scales. Leaves not 
keeled on the upper-side and frequently flat. 
A. Thecone-scales reflexed. The leaves broad, deeply 
keeled on the under-side. Both sides provided 
