STANDLEY FLORA OF GLACIER PARK. 359 



1. OPUL ASTER Medic. 



1. Opulaster malvaceus (Greene) Kuntze. Ninebark. Belton, in woods or on 

 open rocky slopes. B. C. to Oreg., Utah, and Mont. (Pkysocarpus malvaceus 

 Kuntze.) — Shrub, about a meter higli, with loose shredded bark; leaves 2 to 6 cm. 

 wide, stalked, rounded, 3 or 5rlobed and with rounded teeth, glabrous or with 

 branched hairs; flowers white, in dense flat-topped clusters; petals about 5 mm. 

 long; fruit of 2 pods about 5 mm. long. 



A handsome shrub when in flower. 



2. SPIRAEA L. 



Shrubs with toothed leaves; flowers in flat-topped panicles, smoll; fruit of 5 small 

 pods. 



Flowers deep reddish pink 1. S. densiflora. 



Flowers white 2. S. lucida. 



1. Spiraea densiflora Nutt. Pink meadowsweet. Common just above timber 

 line in wet meadows or on open slopes, also in open or brushy places at middle altitudes. 

 B. C. to Oreg., Wyo., and Mont. — Slender shrub, 0.5 to 1.5 meters high, with reddish 

 brown branches; leaves oval or oblong, 1.5 to 3 cm. long, bright green, toothed above 

 the middle, glabrous or nearly so; panicles narrow, dense; petals 1.5 mm. long. 



A showy shrub, with very sweet-scented flowers, which last only a short time. 

 Their fragrance is often noticeable before the plants themselves are seen. 



2. Spiraea lucida Dougl. White meadowsweet. Common at lowland middle 

 altitudes, among aspens, in thin woods, or on open slopes, sometimes extending up 

 to or even above timber line. B. C. to Oreg., Wyo., and Sask. — Low shrub, 30 to 60 

 cm. high, with creeping rootstocks; leaves oval or obovate, 2 t(^ 6 cm. long, glabrous^ 

 rather pale, coarsely toothed; petals 2 mm. long. 



The flowers are nearly odorless; they last a long time. 



3. SERICOTHECA Raf. 



1. Sericotiieca discolor (Pursh) Rydb. Mountain-spray. Frequent at low and 

 middle altitudes, especially on the west slope, in thin woods or on open rocky hill- 

 sides; abundant about Sun Camp; rare in the Many Glacier region. B. C. to Calif, 

 and Mont. — Slender shrub, 1 to 2 meters high; leaves ovate or oval, toothed, 4 to 10 

 cm. long, hairy; flowers creamy wliite, in dense pointed panicles 10 to 20 cm. long; 

 petals 1.5 to 2 mm. long; fruit of small hairy achenes inclosed in the calyx. 



A handsome shrub, which remains in flower nearly all summer. The fiowers'are 

 slightly fragmnt. 



4. POTENTILLA L. Cinquefoil. 



Herbs or shrubs; leaves compound, with 3 or more digitate or pinnate leaflets; 

 flowers in cymes or rarely solitary; petals yellow or sometimes purple; stamens 

 usually 20; fruit of small achenes. 



Plants shrubby 1. P. fruticosa. 



Plants herbaceous. 

 Leaflets 3. 

 Cymes very leafy; leaflets green on both sides; plants not tufted. 



2. P. monspeliensis. 

 Cymes not leafy; leaflets white-woolly beneath; plants in dense tufts or mats. 



9. P. nivea. 

 Leaflets 5 or more. 



Leaves pinnate, some of the leaflets attached along the sides of the petiole. 



Plants with long runners; flowers solitary in the axils of small leaves on the 



runners 16. P. anserina. 



