OCT., 1899.] PLANTS. 1 49 



Spiraea douglasi Hook. Red Spiru'a. 



Common in moist places in the Caniidian and Transition zones, but 

 most abundant in the latter. It is common at Sisson, at the west base 

 of the mountain, and in Scjnaw Creek Valley on the south side, and 

 thence upward, in suitable moist spots, to Waj'on Camp at 5,700 feet, 

 along Squaw Creek at 6,000 feet, ami in Mud Creek Canyon as high 

 as 0,700 feet. 



Horkelia pseudocapitata Uydberg. 



Abundant in the Transition zone near Wagon Camp, particularly 

 about the upper limit of Plniis ponderosa. (Identitied by P. A. Rydberg.) 



Kunzia tridentata (Pursh.) Spreng. 



Irregularly 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 i)lentifully between Black Butte 

 and Shasta Valley. It is almost always associated with Arcfostcqjliylos 

 patuhi, with which it ascends some of the warmer slopes to i)oints far 

 above the npper limit of its usual distribution. Thus it was found on 

 a southwest slojie in Mud Creek Canyon between the altitudes of 0,700 

 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 neighborhood of 

 timberline, where it is common along the little streams in the ui)per 

 edge of the forest, and in the glacial basins which are wet from melting- 

 snows in the early part of the season, l)ut may be dry at the tune the 

 plant blossoms. In damp si)ots, particularly along the borders of cool 

 S]>rings, 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 

 zone. (Identitied by Miss Eastwood and P. A. Rydberg.) 



Potentilla pseudorupestris Rydberg. Dwarf Alpine Potentilla. 



A dwarf Alpine or high Hudsonian Potentilla of the (/hoidnlosa type, 

 collected on the north side of Shastina at an altitude of about 8,800 

 feet, is i)ro vision ally referred to this species by Mr. Rydberg. 



' For ail explanation of this .seemingly abnormal range, see p. 49. 



