STANDLEY FLORA OF GLACIER PARK. 375 



long, finely toothed; flowers very small, greenish, surrounded by a small involucre, 

 borne in the leaf axils; fruit a 3-seeded capsule about 2 mm. thick. 



An inconspicuous plant with milky juice. Some of the related species have a wide 

 reputation in the Southwest as a remedy for rattlesnake bites. 



49. CALLITRICHACEAE. Water Starwort Family. 



1. CALLITRICHE L. Water starwort. 



Aquatic perennials; leaves opposite, entire; flowers minute, sessile in the leaf 

 axils; calyx and corolla none; stamen 1; fruit small, 4-lobed, leathery. 

 Upper leaves spatulate, 3-nerved; flower with a pair of bracts at the base. 



1. C. palustris. 

 Upper leaves (like the others) linear, 1-nerved; flowers without bracts. 



2. C. autumnalis. 



1. Callitriche palustris L. East entrance, in pools. Widely distributed in N. 

 and S. Amer., Eur., and Asia. — Stems usually floating, 3 to 20 cm. long; lower leaves 

 sessile, linear, 1 to 1.5 cm. long, the floating leaves petioled, 5 to 10 mm. long; fruit 

 about 1.5 mm. long. 



2. Callitriche autumnalis L. Occasional in pools or sometimes on mud. Oreg. to 

 Colo., N. Y., and Que.; also in Eur. — Stems slender, 3 to 20 cm. long; leaves 5 to 15 

 mm. long, notched at the apex; fruit 1 to 2 mm. broad. 



50. CELASTRACEAE. Bittersweet Family. 

 1. PACHISTIMA Raf. 



1. Pachistima myrsinites (Pursh) Raf. Mountain lover. Abundant on the 

 west slope and in some localities on the east slope, usually in woods. B. C. to Calif. 

 N. Mex., and Alta. — Shrub, 20 to 60 cm. high; leaves opposite, evergreen, oval or 

 obovate, 1 to 3 cm. long, somewhat toothed; flowers small, green, clustered in the 

 leaf axils; petals 4; fruit a small 2-celled capsule. 



Rare in the Many Glacier region, but the shrub grows in one place along the trail 

 to Swiftcurrent Pass; plentiful about Sun Camp. It is an inconspicuous and 

 unattractive plant, with erect or sometimes prostrate branches. 



51. ACERACEAE. Maple Family. 

 1. ACER L. Maple. 



1. Acer douglasii Hook. Mountain maple. Common at low and middle alti- 

 tudes, usually in woods or thickets, sometimes on open slopes. B. C. to Oreg., 

 Wyo., and Alta. — Shrub, or a small slender tree with smooth gray bark; leaves 

 opposite, slender-petioled, 3 to 10 cm. long and about as broad, glabrous, 3 or 5-lobed 

 and toothed, on young branches often divided into 3 leaflets; fruit of 2 samaras, 

 these 3 to 4 cm. long. 



The plants are very .variable in size and in form of the leaves. In exposed places 

 the plants are usually shrubs, about a meter high, forming large clumps, or small 

 trees. In woods they are more often slender trees. The leaves are often covered 

 with showy, bright red galls. It is doubtful whether A. douglasii is more than a 

 form of A. glabrum Torr. 



52. RHAMNACEAE. Buckthorn Family. 



Fruit juicy; flowers green, clustered in the axils of the leaves .... 1. RHAMNUS. 

 Fruit dry; flowers white, in panides 2. CEANOTHUS. 



