38 



APPENDIX B: Vascular plants identified in the Horse Prairie 

 Creek study area. Taxa in bold typeface were collected; 

 specimens will be deposited at the herbarium at Montana State 

 University (MONT). An asterisk (*) following the name designates 

 a taxon which is adventive to this continent (Eurasian weeds). 

 The total number of taxa is 329 in 52 families. Twenty nine 

 species are adventive from Eurasia. 



PTERIDOPHYTES 



ADIANTACEAE 

 Chielanthes feei 



EQUISETACEAE 

 Eguisetum arvense 



SELAGINELLACEAE 

 Selaginella densa 



GYMNOSPERMS 



CUPRESSACEAE 

 Juniperus communis 

 J. scopulorum 



PINACEAE 

 Picea engelmannii 

 Pinus contorta 

 P. flexilis 

 Pseudotsuga menziesii 



ANGIOSPERMS 



APIACEAE 

 Angelica arguta 

 Cymopterus nivalis 

 Heracleum sphondylium 

 Lomatium triternatum 

 Osmorhiza depauperata 

 0. occidentalis 

 Perideridia gairdneri 



ASTERACEAE 

 Achillea millefolium 

 Agoseris glauca 

 Anaphalis margaritacea 

 Antennaria anaphaloides 

 A. microphylla 

 A. racemosa 

 Arnica cordifolia 

 A. sororia 



Artemisia frigida 



A. ludoviciana 



A. nova 



A. tridentata 



var. tridentata 

 var. vaseyana 



A. tripartita 



Aster foliaceus 



A. modestus 



A. scopulorum 



Balsamorhiza sagittata 



Carduus nutans* 



Chaenactis douglasii 



Chrysothamnus nauseosus 



C. viscidif lorus 



Cirsium arvense* 



C. canovirens 



C. hookerianum 



C. scariosum 



C. undulatum 



C. vulgare* 



Crepis acuminata 



C. modocensis 



C. runcinata 



Erigeron caespitosus 



E . compositus 



E. corymbosus 



E. pumilus 



E. tweedyi 



Gaillardia aristata 



Grindelia squarrosa 



Gutierrezia sarothrae 



Haplopappus acaulis 



H. suf f ruticosus 



Helenium autumnale 



Helianthella uniflora 



Heterotheca villosa 



Hymenopappus filifolius 



Machaeranthera canescens 



Matricaria matricariodes 



Microseris nutans 



Nothocalais troximoides 



