regions to study how the vegetation of the humid taiga must gradually give way to the 

 xerophilous steppe vegetation that advances in proportion as we get more and more south, 

 away from the higher mountains. Owing to the broiling sun the plants were mostly dry 

 and withered already in the middle of August when I visited these regions. About the 



above sea. 



Fig. 52. Typical scenery from tlie wooded steppe region on the 

 Upper Bei-liem, near Ust Tara kem. The trees are birch and larch. 



Kamsara, roughly 35 — 40 wersts south of Ust Sisti-kem, the taiga has completely dis- 

 appeared, the land farther to the south consisting wholly of steppes, alternating with 

 the open wooded steppes. 

 Vegetation at On the Kamsara I collected a series &f plants, on the whole indicative of a con- 



Ust Kamsara, siderably drier climate than farther north. On dry, open declivities the following plants, 

 particularly belonging to the steppe region, occurred: 



Caragana arborescens, Rosa pimpindli folia, Spiraea hypericifolia, Cotoneastei 

 melaiiocarpa, Dianlhus rhinensis, Seduni hybridum, Thymus Serpyllum, Dracocephalum 

 nutans, Dracocephalum Ruyschiana, Phlomis tuberosa, Thermopsis lanceolata. Astragalus 

 fruticosus, Triticum cristalum, Potentilla subacaulis, Fragaria collina, Peucedanum 

 baicalense, G<dium varum, Galatella punctata, Artemisia sacrorum, Artemisia frigida. 

 Campanula glomerata, Origanum vulgare, Galeopsis Tetrahit, Phleum Boemeri subspec. 

 decurtatum, Triticum caninum, Aconitum barbatum, Scabiosa ochroleuca. Cotyledon 

 spinosa, Atraphaxis frutescens, and Ephedra vulgaris. 



Growing especially in larch-forest: 



Aster alpinus. Polygonum undulatum var. alpinum, Chamaeihodos erecta, Potentilla 

 fruticosa, Rubus saxatilis, Solidago Virgaurea, Gentiana Amarella, Euphorbia Esula, 

 Triseium flavescens subpec. copiosum nov. subspec, and Bromus inermis. 



82 



