Southern Park Mountain District. 559 
Massed in great ums over the surface of the bogs are Gentiana serrata (= G. detonsa , 
G Forwoodl, Senecio lugens, S. subnudus, er us Fee Trifolium longipes, Polygonum 
viviparum, Parnassia fimbriata, Habenaria hyperborea, Pedicularis groenlandica, P. brodiaea, P. 
racemosa, Valeriana edulis, while as secondary species ee Vak the taller ones are Stell- 
aria (Alsine) borealis, S. longipes, S. erishtfeie, Androsace filiformis, A. septentrionalis, Wyethia 
helianthoides is a striking plant ud such grasses as Phleum alpinum, Bromus breviaristatus, B. 
ciliatus, B. Kalmii are found?). 
3. Vegetation of the Geyser and Hot Springs. 
This formation is confined to the Yellowstone Park. The alkaline nature 
of the soil and the warmth afforded by the hot spring and geyser areas have 
influenced the distribution of species to a marked extent. Such seashore 
plants as -Salicornia herbacea, Rumex maritimus (= R. persicarioides) and 
Triglochin maritima are found. The barren soil supports few plants but where 
overlaid by other soil or where the species grow along streams occurs a 
luxuriant vegetation of Chrysopsis villosa, Gnaphalium Sprengelü, Panicum 
Eh var. pubescens. Ruppia maritima has been observed in water with 
o°F. of heat. The small streams are filled with Pofamogeton pectinatus, while 
Big hium ternatum var. australc has never been observed out of hot spring 
soil. Ihe bare geyserite supports Sfpraguea umbellata, Castilleia minor, 
Orthocarpus luteus and Glyceria atroides?). 
The following plants have not been observed on soils other than that due to the hot springs: 
Aplopappus uniflorus Torr. and Gray. | Juneus tenuis Willd. var. congestus 
Lycopus virginicus L. var, pauciflorus Benth. Engelm. 
Eriogonum flavum Nutt. Spartina gracilis Trin. 
e geysers are actively throwing up in jets at periodie intervals, steam and boilling water; 
the . springs are either quiescent, or are bubbling without explosive eruption. They are 
found in four distinet areas in the Park; the geysers and the hot springs in the Upper, Lower 
and Norris Geyser Basin, hot springs only in the Mommoth Hot Spring Region. This division 
also accords with the predominating chemie content of the waters. In the Dee Lower and 
Norris Geyser Basins, we have springs and geysers which are actively depositing silieious material 
(sinter); in the Mammoth Hot Spring Basin, springs which are forming calcareous Gere; called 
travertine?) (see plate XII). 
hot springs of the Yellowstone no plant life has been found at a temperature ex- 
ceeding 185° F., some degrees below the boiling point of water, which, at the altitude of the 
park (7,000—8,500 feet) is 198° F. The most luxuriant growth of algae is found in water which 
has cooled down to a temperature of 104° F. to 125° F.; (= 40° C. to 52°C?) in such water 
we have the greatest display of RR because rege : en can live in water of that degree 
of heat. In the hottest waters (185° F.= 85,4°C.) o white filamentous bacteria are found, 
which gradually become of a sulphur-yellow color at a F. (80° C. 
WEEDY, FRANK: Notes on the Flora of Veibwstone Park. Bulletin ae Botanical 
a). Tonaor; Ioe ce Pe 
3) HARSHBERGER, JOHN w. Vegetation of the Yellowstone hot Springs. American Journal 
of Pharmacy LXIX.; 625. Dec. 1897. 
