ROSE FAMILY 405 



late, nearly 3 mm. long, white; follicles 2-2.5 mm. long. Cliffs in the mountains: 

 Mont. — n Wyo. — -Ida. Submont. — Mont. Jl. 



5. LUETKEA Bong. 



Cespitose imdeishrubs, with decumbent or creeping, stoloniferous branches. 

 Leaves twice or thrice ternately dissected, grooved above. Flowers perfect, 

 racemose. Hypanthium hemispheric. Sepals 5, valvate. Petals 5, while in 

 bud contorted. Stamens about 20; filaments subulate, connate at the base; 

 anthers didymous. Disk thickened, about 10-lobed. Pistils 4-6, usually 5, 

 distinct; styles terminal, deciduous; stigmas trimcate; ovules several, pendu- 

 lous. Follicles coriaceous, dehiscent on both sutures. Seeds hnear-lanceolate, 

 acute at both ends. 



1. L. pectinata (Pursh) Kuntze. Flowering shoots 5-15 cm. high, leafy, 

 glabrous; leaves 1-1.5 cm. long, dissected into linear, acute divisions, glabrate; 

 raceme short, 1-5 cm. long; bracts ternate or the upper ones entire; hyjianthium 

 about 2 mm. wide; sepals ovate, acute, 2 mm. long, glabrous; petals white, 

 orbicular or rounded-obovate, 3-3.5 mm. long; carpels about 4 mm. long. Erio- 

 gynia pectinata Hook. Spiraea pectinata T. & G. Moimtains: Alaska — Ore. — • 

 Alta. Mont. Jl-S. 



6. ARtJNCUS (L.) Adans. Goat's Beard. 



Perennial herbs, with thick rhizomes, twice or thrice ternate-pinnatisect 

 leaves, and no stipules. Inflorescence a large panicle with spike-like branches. 

 Flowers dioecious. Hypanthium of the staminate flowers flat or saucer-shaped, 

 pentagonal. Sepals triangular, valvate. Petals 5, orbicular to spatulate, white. 

 Stamens 15-30; filaments subulate, distinct, long-exserted ; anthers didymous. 

 Disk 5-lobed. Pistils 3-5, rudimentary, style-less. Pistillate flowers much 

 smaller. Petals elliptic to oblanceolate. Stamens rudimentary; filaments 

 short; anthers minute, empty. Pistils 3-5, distinct; styles short, obUquely 

 terminal; stigmas capitate; ovules 8-12, pendulous. Folhcles oblong, cartil- 

 aginous, dehiscent along the ventral suture and then splitting dorsaUy at the 

 apex, in our species reflexed. Seeds few, attenuate at both ends. 



1. A. acuminatus (Dougl.) Rydb. Stem 1-2 m. high, glabrous; leaflets 

 3-12 cm. long, lanceolate, long-acuminate at the apex, truncate or subcordate 

 at the base, sharply and doubly serrate; panicles terminal and axillary, 1-4 dm. 

 long; petals of the staminate flowers broadly rounded-obovate, about 1 mm. 

 long, those of the pistiUate flowers slightly smaller, elliptic; folhcles about 3 mm. 

 long and 1 mm. thick, shining. A. Sylvester Coult. & Nels., not Kost. Moist 

 woods and along streams: Ore. — Alaska — B.C. Mont. Je-S. 



7. CHAMAEBATIARIA (Porter) Maxim. Fern-bush. 



Low shrubs, more or less stellate-pubescent and scurfy, with bipinnatisect 

 leaves and paniculate flowers. Hypanthium turbinate. Sepals 5, erect, imbri- 

 cate. Petals 5, rounded, erect. Stamens about 60, inserted on the margin of 

 the disk. Pistils 5, more or less united below; styles terminal; stigmas capitate; 

 ovules about 8, pendulous. Follicles coriaceous, dehiscent on the ventral suture 

 and at the apex on the dorsal one; seeds few, terete, not appendaged. 



1. C. Millefolium (Torr.) Maxim. A densely branched shrub, less than 

 1 m. high; leaves 2-4 cm. long, crowded at the ends of the branches, glabrous 

 above, stellate-tomentose beneath, oblong in outline; primary divisions about 

 20 pairs, 4-8 mm. long; secondary divisions 15-17 pau-s, decurrent, about 0.5 

 mm. long, entire, obovate; panicle 3-10 cm. long, leafy below; sepals lanceolate- 

 deltoid, acute, 3 mm. long; petals white, rounded-obovate, about 5 mm. long, 

 wavy and crenulate; follicles about 5 mm. long. Spiraea Millefolium Torr. 

 Among rocks: Ida. — Nev. — Ariz. — s Calif. Submont. — Mont. Jl-S. 



8. SERICOTHECA Raf. Ocean Spray, Mountain Spray. 



Shrubs, with simple toothed or lobed leaves. Sepals 5, 3-nerved, valvate 

 in the bud, in fruit erect. Petals 5, white or pinkish, short-clawed. Stamens 



