ROSE FAMILY 223 



Leaves without punctate glands, apparently deciduous 1. p, tridentata. 



Leaves with punctate glands, apparently evergreen 2. P. glandulosa. 



1. P. tridentata DC. Antelope Brush. Diffusely branched silvery or gray 

 shrub 1% to 10 feet high; bark gray or brown; leaf -blades cuneate, 3-toothed at 

 apex, thinly pubescent and green above, white-pubescent below, 3 to 8 lines long; 

 calyx pubescent, thickly sprinkled with resin granules; calyx-lobes pubescent; 

 petals pale yellow, obovate, 3 to 5 lines long, filmy. 



Arid slopes and dry valleys, 4000 to 7000 (or rarely 11,000) feet : east slope and 

 east Summit valleys of the Sierra Nevada from Tulare and Inyo Cos. to Modoc Co., 

 thence west to northern Trinity Co. East to the Rocky Mts., north to Oregon. 

 May-Aug. 



Field note. — The bushes of Purshia tridentata often consist of several or many stems from 

 the base. The light brown bark is very shreddy; on the younger branches it is smooth and is 

 reminiscent of peach or plum bark. In Lassen Co. the bush is a valued winter forage when snow 

 is on the ground, since cattle and sheep browse the shoots of the past season. It is also called 

 Bitter-brush, Greasewood and Buck -brush. 



Locs. — Little Kern Eiver, near Trout Mdws., Jepson 4916; Green Lake, w. Inyo Co., ace. 

 Peirson (nearly prostrate) ; Bloody Canon, Mono Co., Chesnut 4" Drew; Fales Hot Sprs., Alpine 

 Co., Ottley 1034; Brockway, Lake Tahoe, Jepson 7741; Truckee, L. S. Smith; Loyalton, Sierra 

 Co., L. S. Smith; Cherry Peak, Plumas Co., ace. W. I. Follett; Long Valley, Lassen Co., Jepson; 

 Honey Lake Valley, Jepson; Hot Springs Valley, Lassen Peak, Jepson 4076; Davis Creek, Modoc 

 Co., Jepson 7831; upper Fall River VaUey (lava fields ne.), Jepson; McCloud, Jepson; Sisson, 

 Mt. Shasta, Jepson 13,843 ; Yreka, Butler 285; Salmon Mts., Trinity Co., Hall 8651. 



Refs. — PuKSHiA TRIDENTATA DC. Trans. Linn. Soc. 12 : 158 (1818) ; Hook. Fl. Bor. Am. 1:170, 

 pi. 58 (1834); Lindl. Bot. Reg. t. 1446 (1831); Jepson, Man. 504, fig. 502 (1925). Tigarea 

 tridentata Pursh, Fl. 333 (1814), "prairies of the Rocky Mts." (Montana), Lewis. Kunzia 

 tridentata Spr. Sys. 2:475 (1825). 



2. P. glandulosa Curran. Dark green shrub 2 to 4 (or 8) feet high; bark 

 dark red or gray; leaf -blades divided above into 3 (rarely 5) linear lobes, or some- 

 times merely 3-toothed, narrowed below to a petiole-like base, nearly glabrous, 2 to 

 4% lines long, the revolute margin with conspicuous glandular dots or pustules; 

 petals white; calyx and fruit canescent. 



Desert slopes or arid flats, 4000 to 9000 feet : mountains on west side of Colorado 

 Desert; Mohave Desert; Inyo and Mono Cos. East to Nevada. Apr.- July. 



Field note. — In the White Mts. Purshia glandulosa grows 1 to 3 feet high and twice as 

 broad, forming low broad bushes in the open Hickory Pine (Pinus aristata) forest, producing an 

 effect similar to that of Snow Brush (Ceanothus cordulatus) in the higher Sierra Nevada conif- 

 erous forest. 



Locs. — Live Oak Sprs., s. San Diego Co., Jepson 11,830; Kenworthy, San Jacinto Mts., 

 Muns 5499 ; Pinon "Wells, mts. n. of Mecca, Jepson 5988 ; Rock Creek, San Gabriel Mts., Peirson 

 80; Palmdale, w. Mohave Desert, Davidson; Mt. Pinos, Ventura Co., Muns 7001; Kelso, San 

 Bernardino Co., Jones; New York Mts., Jepson 5439; Argus Mts., Purpus 5738; Cottonwood 

 Creek, Inyo Co., Jepson 5088; Silver Canon, White Mts., Jepson 7225; Benton, Mono Co., ace. 

 •7. Grinnell. 



Refs. — PuESHiA GLANDULOSA Curran, Bull. Cal. Acad. 1:153 (1885), type loc. on Mohave 

 side of Tehachapi Pass, Curran; Jepson, Man. 504 (1925). Kunzia glandulosa Greene, Pitt. 

 2:299 (1892). Purshia tridentata var. glandulosa Jones, Proc. Cal. Acad. ser. 2, 5:680 (1895). 



24. OSMARONIA Greene 



Shrub with simple entire deciduous leaves and caducous stipules. Flowers 

 dioecious, white, fragrant, in nodding racemes terminating leafy branchlets. Stam- 

 inate flower with spreading petals; stamens 15, in 3 rows, 10 inserted with the 

 petals, 5 inserted lower down upon the disk lining the calyx-tube. Pistillate flower 

 with erect petals; stamens present but abortive; pistils 5, distinct; styles short, 

 lateral, jointed at base. Fruit consisting of 1 to 5 drupes. Drupes ovoid, 1-seeded, 

 with a thin pulp and bony stone. — Species 1, western North America. (Greek, 

 osme, fragrant, and Aronia, a Rosaceous genus proposed by Persoon.) 



