RYDBERG: PHYTOGEOGRAPHICAL NOTES 303 
d. Hillside plants 
Panicum Huachucae _ Balderdykia Convolvulus (Eur.) 
Ibidium strictum Pulsatilla ludoviciana 
Polygonum Douglasii 
B. TRANSCONTINENTAL SPECIES RESTRICTED TO THE NORTHERN 
ROCKIES 
Nearly all of the transcontinental plants restricted in their 
distribution to the Northern Rockies are of boreal-sylvan distribu- 
tion, whether they are forest species or not. In spreading across 
the continent, they have followed the northern woods around the 
plains north of the Saskatchewan and then south in the mountains. 
In some cases the species have not extended very far south— 
have not even entered the United States; in other words, their 
distribution in the Rockies is limited to District 1, the Canadian 
Rockies. Others have traveled farther south and invaded Dis- 
trict 2, or even Districts 3 and re About one third have spread 
further south into District 5 and from there to Districts 6, 7 and 8. 
Two are even found in the Uintah-Wasatch District of the Southern 
Rockies. 
I. SPECIES REACHING AT LEAST THE YELLOWSTONE DISTRICT 
a. Forest plants 
Sabina horizontalis Androsace septentrionalis (Eur.) 
Melica Smithit Valeriana septentrionalis 
Oryzopsis pungens Aster major 
Carex Peckii Aster Lindleyanus 
Streptopus amplexifolius Youngia nana (Asia){ 
Rosa acicularis (Asia) Aspidium viride (Eur.) 
Osmorrhiza divaricata 
b. Water and bog plants 
Eriophorum Scheuchzeri (Eur.)t Comarum palustre (Eur.) 
Eriophorum Chamissonis (Eur.)} Equisetum palustre (Eur.) 
Carex livida Equisetum fluviatile- 
Juncus Richardsonianus Equisetum laevigatum 
