322 RYDBERG: PHYTOGEOGRAPHICAL NOTES 
the Rockies and are in reality immigrants from the Upper Sonoran 
region, as for instance, Populus Wislizenti, Grossularia leptantha, 
Blepharoneuron tricholepis, Calamagrostis scopulorum, Festuca 
arizonica and Fragaria ovalis. 
As I have stated elsewhere, the interchange of flora between — 
the Southern Rockies and the Northern does not take place so 
much along the continental divide in central Wyoming as from the 
Wasatch Mountains, over the Bear River Mountains and the 
- Tetons, to the Northern Rockies. Several southern species are 
found in the two intermediate ranges mentioned and several 
northern ones in the Wasatch. These southern species are as 
follows: 
Shrub 
Salix Wolfit 
Herbs 
Stipa Vaseyi Primula Parryt 
Rumex densiflorus Orthocarpus purpureo-albus 
Ranunculus intertextus Penstemon subglaber 
Delphinium occidentale Penstemon Rydbergu 
Delphinium reticulatum Aster Canbyt 
Cardamine cordifolia Senecio perplexus 
Arabis divaricarpa Senecio rapifolius 
Potentilla filicaulis Senecio uintahensis 
Sidalcea neomexicana Cirsium Eatont 
Amarella monaniha Leontodon scopulorum 
The following plants of the Southern Rockies extend into the 
Black Hills or western Nebraska. 
Poa andina Ceanothus Fendleri 
Eriogonum pauciflorum Cynomarathrum Nuttall 
Arabis Fendleri Dodecatheon radicatum 
Draba auriformis Sambucus microbotrys 
Saxtfraga simulata Thelesperma gracilis 
Potentilla propinqua Senecio spartioides 
Opulaster monogynus — Senecio rapifolius 
