1908] Grinnell—Biota of the San Bernardino Mountains. 49 
Artemisia tridentata Nuttall. 
The true sage-brush was abundant over the upper levels and 
slopes facing the desert, but not nearly down to the desert itself. 
It occupied only the lower Transition and Upper Sonoran zones. 
Large tracts in Bear and Holeomb valleys were occupied by it 
almost exclusively. It occurred commonly down the upper Santa 
Ana, especially along the north wall, to as low as Seven Oaks, 
5100 feet altitude. (See pls. 38, 24, 16n.) 
Chrysothamnus tortifolius (Gray) Greene. 
This shrub was common in sandy washes in the Transition 
zone both on the desert and Pacific slopes, blooming in August. 
It was collected in Bear valley and on the upper Santa Ana. 
Chrysothamnus nauseosus graveolens (Nuttall) Piper. 
The rabbit brush was abundant in sandy washes both on the 
desert and Pacific slopes. Along the upper Santa Ana it was 
abundant, as also from Bear lake eastward, mingling with the 
sage. Named by Dr. Hall. 
Tetradymia canescens De Candolle. 
Noted commonly in the sage belt, Upper Sonoran and lower 
Transition, mostly on the desert slopes. It was taken at Big 
Meadows, head of the Santa Ana, and at Doble; bloomed the last 
of July. 
Carduus Bernardinus Greene. 
This tall thistle was abundant in the lower Transition zone, 
5000 to 7000 feet altitude, in the region of the upper Santa Ana. 
Carduus Drummondii acaulescens (Gray) Coville. 
The stalkless thistle was common in the region of the upper 
Santa Ana (Transition zone), growing in grassy, but not very 
wet, swales. Noted from 6000 to 7000 feet altitude. 
Erigeron compositus discoideus Gray. 
Collected on gravel among rocks on the summit of San Gor- 
gonio peak, 11,450 feet, July 16, 1906. Determined by Dr. Hall. 
