STANDLEY FLOKA OF GLACIER PARK. 327 



1. Eriogonum piperi Greene. Sulphur-plant. Common at nearly all altitudes on 

 the east slope, on open rocky hillsides; abundant on rock slides above timber line. 

 Wash, to Wyo. and Mont. — Plants usually forming dense clumps; leaves oblanceolate, 

 stalked, obtuse, 3 to 10 cm. long, densely woolly beneath, green and thinly silky on 

 the upper surface; involucres in a large umbel; sepals about 5 mm. long, often 

 becoming deep red in age. 



It is doubtful whether this is more than a mere form of E. flavum Nutt. 



2. Eriogonum androsaceum Benth. On rock slides and exposed summits above 

 timber line, rare in most places; occasionally found in exposed places at low altitudes. 

 B. C, Alta., and Mont. — Often forming dense mats; leaves oblanceolate or epatulate, 

 1 to 2 cm. long, densely woolly or becoming green on the upper surface; involucres 

 in a small umbel; flowers 4 to 5 mm. long, sometimes tinged with pink. 



3. Eriogonum subalpinum Greene. Umbrella-plant. Common on the east slope 

 at nearly all altitudes, on open hillsides or in meadows. B. C. to Nev., Colo., and 

 Alta.— Plants 15 to 40 cm. high, usually forming loose patches; leaves elliptic, ovate> 

 or obovate, 1.5 to 5 cm. long, green on the upper side and glabrous or nearly so, densely 

 white-woolly beneath; flowers greenish white or tinged with pink, 4 to 5 mm. long. 



4. Eriogonum depressum (Blankinship) Rydb. Silver-plant. Common on the 

 east slope at high and middle altitudes, on rock slides or open rocky hillsides. Greg, to 

 Mont.— Plants 5 to 15 cm. high, usually forming small dense mats; leaves rounded or 

 broadly ovate, 5 to 15 cm. long, white, long-stalked; flowers 3 to 4 mm. long, yellowish 

 white, often tinged with pink. 



The name "silver-plant" was applied to this and related species by prospectors 

 because the plant was believed to indicate the presence of silver deposits. 



2. POLYGONUM L. 



Annuals or perennials, sometimes growing in water; leaves alternate, entire; flowers 

 solitary or clustered in the axils of the leaves or in spikes. 



Stems climbing; leaves triangular, with lobes at the base 1. P. convolvulus. 



Stems not climbing; leaves never triangular. 



Flowers in dense spikes, not bracted, white or deep pink. 

 Flowers deep pink; stems very leafy, often branched and bearing several spikes. 



Leaves acute, with fine appressed hairs 2. P. muhlenbergii. 



Leaves obtuse, glabrous 3. P. amphibium. 



Flowers white ; stems with small leaves, not branched . 



Spikes 10 to 15 mm. thick, without bulblets 4. P. bistortoides. 



Spikes 5 to 6 mm. thick, bearing bulblets below 5. P. viviparum. 



Flowers mostly in the axils of the leaves, sometimes in spikes but then with leaflike 

 bracts at the base of the flowers, greenish. 

 Flowers bent downward in fruit. 



Lower leaves oval or rounded 6. P. austinae. 



Lower leaves linear or lanceolate. 



Flowers 1".5 to 2 mm. long; leaves all linear 7. P. engelmannii. 



Flowers 3 to 4 mm. long; leaves linear or more often lanceolate. 



8. P. douglasil. 

 Flowers erect, never bent downward. 

 Flowers crowded near the ends of the stems, the inflorescence spikelike; bracts 



with broad white margins 9. P. polygaloides. 



Flowers solitary or clustered in the axils of the leaves; bracts without white 

 margins. 



Stems red, slender, wiiy, not ridged 10. P. minimum. 



Stems pale green, stout, ridged. 

 Stems usually prostrate; sepals with white or pink edges. 



11. P. aviculare. 



