ocr., 1899.] PLANTS. 149 
Spirea douglasi Hook. Red Spiriva. 
Common in moist places in the Canadian and Transition zones, but 
most abundant in the latter. It is common at Sisson, at the west base 
of the mountain, and in Squaw Creek Valley on the south side, and 
thence upward, in suitable moist spots, to Wagon Camp at 5,700 feet, 
along Squaw Creek at 6,000 feet, and in Mud Creek Canyon as high 
as 6,700 feet. 
Horkelia pseudocapitata Rydberg. 
Abundant in the Transition zone near Wagon Camp, particularly 
about the upper limit of Pinus ponderosa. (Identified by P. A. Rydberg.) 
Kunzia tridentata (Pursh.) Spreng. 
Trregularly distributed in the Transition zone; commonest in the 
manzanita chaparral of the lower slopes. On the north side of the 
mountain it is exceedingly abundant, and in the open pine forest bor- 
dering the south end of Shasta Valley attains unusually large size. 
On the west side, north of Sisson, it occurs sparingly on most of the 
warmer and drier knolls, and more plentifully between Black Butte 
and Shasta Valley. It is almost always associated with Arctostaphylos 
patula, with which it ascends some of the warmer slopes to points far 
above the upper limit of its usual distribution. Thus it was found on 
a southwest slope in Mud Creek Canyon between the altitudes of 6,700 
and 7,400 feet; on similar slopes near Horse Trail and in Diller Canyon 
as high as 7,800 to 7,900 feet, and on a warm pumice ridge north of 
Shastina at 7,500 feet... In Squaw Creek Valley, near McCloud Mill, a 
form occurs which has exceedingly narrow leaves. 
Lutkea pectinata (Hook.) Kuntze. 
Abundant in the Hudsonian zone, chiefly in the neighborLood of 
timberline, where it is common along the little streams in the upper 
edge of the forest, and in the glacial basins which are wet from melting 
snows in the early part of the season, but may be dry at the time the 
plant blossoms. In damp spots, particularly along the borders of cool 
springs, the individual plants often stand so near together as to form 
extensive beds. 
Potentilla flabellifolia Hook. 
Occurs here and there, a little below timberline, in the Hudsonian 
zope. (Identified by Miss Eastwood and P. A. Rydberg.) 
Potentilla pseudorupestris Rydberg. Dwarf Alpine Potentilla. 
A dwarf Alpine or high Hudsonian Potentilla of the glandulosa type, 
collected on the north side of Shastina at an altitude of about 8,800 
feet, is provisionally referred to this species by Mr. Rydberg. 
' For an explanation of this seemingly abnormal range, see p. 49. 
