curl up on the edges preparatory to falling off and so roughen slightly the surface. The leaves on the axis of young trees may and often do persist 11 years; on lateral branchlets 3 or 4 yrs, when a tree begins to bear cones (even if it be young) the leaves on the main axis persist but 3 or 4 years. The cones persist 2 to 4 years; on dead limbs they may hang until the limb falls. I noted local areas where the main axis was replaced b a broom-like tuft of 3 to 6 or 9 leading shoots. Witches brooms are not at all uncommon in this region on this species.
July 27, 1906.
No. 2556. Epilobium. Wet ground. Willow Camp.
No. 2557. Gentian. Ditto
No. 2558. Rosaceae. "
No. 2559. Compositae. Dry ground. Willow Camp. Great dif. in achenes! in length.
- Populus tremuloides. Common in clumps on steep hillsides and on edges of swamps between Mammoth Hot Springs and Livingstone. Also noted in the Park at Grand Ca_on Yellowstone. Bark white, often with a pale greenish or yellowish cast. Mostly 4 to 10 ft. or sometimes 20 ft. high. There is also Spruce, Douglas Spruce, and Pinus flexilis, a little of each.