1 10 American Midland Naturalist Monograph No. 4 



Leaflets oblong-lance-shaped, pointed at the tips; found in Rocky Mountain parks 

 and the Southwest. 

 Shrubs to 12 feet high; leaflets 11 to 13, IJ/^ to lYi inches long, shiny-green 



above; found in Rocky Mountain parks 3. 5. scof.ulina. 



Shrubs to 9 feet high ; leaflets 9 to 1 1 , % to 1 ^ inches long, dull green above, 



found in the Southwest 4. 5. dumosa. 



1. Western Mountain Ash, Alpine Mountain Ash (Sorbus oc- 

 cidentalis (Wats.) Greene). — Shrubs 3 to 9 feet tall; bark gray; winter buds 

 and young twigs more or less hairy; leaflets 7 to 11, thinnish, dull green 

 above and below, narrowly elliptic to oval, % to 21/2 inches long, rounded 

 or flattish at the tip, toothed only at the tip or not at all; flower clusters 1 to 

 1^2 inches across, rounded; berries red, covered with a bloom. 



Occurrence. — OLYMPIC, 4,000 to 7,000 feet: Baldy Peak; Seven Lakes Basin; 

 Marmot Lake. MOUNT RAINIER, common, 4,500 to 7,000 feet: Goat Island Mountain; 

 Mazama Ridge; Paradise Park. 



2. Pacific Mountain Ash (Sorbus s'tcbensis Roem.), fig. 48. — Many- 

 stemmed shrubs 3 to 12 feet high; winter buds and young twigs thinly hairy; 

 leaflets 9 to 15, oval to oblong, % to 3 inches long, rounded to broadly- 

 pointed at the tips, coarsely and sharply toothed to the middle or below, 

 dull or somewhat shiny green above, paler below; flower-clusters 2 to 5 inches 

 across, somewhat round-topped, the flower stems smooth or thinly hairy; 

 berries red, without a bloom. (Syns. S. californica Greene, S. cascadensis 

 Jones.) 



Occurrence. — Olympic, occasional, 2,000 to 4,000 feet: lower slope of Mount Nor- 

 ton, Elwha River valley; Dosewallips River. MOUNT RAINIER, common, 2,000 to 5,000 

 feet: Bear Prairie; Frog Heaven. CRATER LAKE: rim road to Lost Creek; Castlecrest 

 Garden, 7,000 feet. LASSEN : Mount Lassen ; Lcng Lake. YOSEMITE, common, 7.000 to 

 10,000 feet: Ledge trail; Chilnualna Falls; Dog Lake, near Tuolumne Meadows; 

 Gaylor Lakes; Tioga Pass; Isberg Pass trail; Bridal Veil gorge; Snow Creek. KINGS 

 CANYON: between Junction Meadcw and Charlotte Creek; Bubbs Creek opposite Char- 

 lotte Creek campgrounds. SEQUOIA, occasional, 9,000 to 10,000 feet: Cliif Creek; trail 

 below Tamarack Lake; Emerald Lake; near Alta Peak; Farewell Gap. GLACIER, 

 occasional, 3,000 to 7,000 feet: Lake McDonald; Snyder Lake; Sperry Chalet; Gun- 

 sight Lake; Granite Park; Grinnell Lake; trail to Ptarmigan Lake. 



Variety densa Jepson, with the leaflets more crowded, the flower-clusters 

 denser, and the flowers hairy at the base, has been described from Stubble- 

 field Canyon in Yosemite National Park. 



3. Greene's Mountain Ash (Sorbus scopulina Greene), fig. 49. — 

 Rather stout shrub 3 to 12 feet high; winter buds more or less sticky, some- 

 times with a few hairs; leaflets 11 to 13, li^ to 2% inches long, oblong-lance- 

 shaped, pointed at the tip, toothed nearly to the base, dark green and glossy 

 above, paler beneath; flower clusters 3 1/4 to 6 inches across, flat-topped; fruits 

 bright orange-red, without a bloom. 



Occurrence. — GLACIER, abundant, 3,000 to 6,000 feet: Belton; Lake McDonald; 

 Cattle Queen snowshoe cabin; Logan Pass; St. Mary Lake; Gunsight Lake; Cut Bank 

 Valley; Two Medicine Lake and valley; Swiflcurrenf La'^e and valley; Crossley 

 Lake. YELLOWSTONE, common, 6,000 to 8,000 feet: near Old Faithful; west of Thumb; 



