IOWA ACADEMY OF SCIENCES. 
99 
SOME INTRODUCED AND WEEDY PLANTS. 
The irrigated and lower unirrigated districts contain a 
largenumberof foreign weedy plants. The more conspicuous 
of the weedy plants of grain fields are such as are com- 
mon to all the inter-mountain country. The Avena fatua^ 
Saponaria vaccaria^ Lychnis githago, lielianthus petiolaris, 
and H. aniiuus, Brassica sinapistrum. The more common 
of the street and roadside weeds observed were as follows: 
The Sisymbrium aliissimum was as common in the streets 
of Hamilton as Brassica sinapistrum is in eastern North 
Dakota or along the roadsides in Iowa. Cnicus lanceolatus, 
abundant not only in the streets but in dry places along 
the roadsides. Rumex acetosella, Chenopodium album, Salsola 
kaliY?iY. tragus, Cnicus canescens, Verbascum thapsus, V. blat- 
taria Lactuca pulchella were common not only along 
roadsides where the soil was occasionally irrigated, but in 
very dry soils. The Black Henbane {Hyoscyanus niger) 
was found in one place along the roadside close to the 
mouth of the west branch of the Bitter Root river. 
It is interesting to make a comparison of the weedy 
plants found near Deer Lodge, Montana, the Deer Lodge 
being a tributary of the Hellgate, which in turn empties 
into the Missoula. 
The Arena fatua, Saponaria vaccaria. Lychnis githago, 
Helianthus petiolaris, H. annuus, Hordeum jubatum, Bras- 
sica sinapistrum, Salsola kali var. trcCgus, are common not 
only in Deer Lodge but near Livingston, Billings, Miles 
City and Glendive on the Atlantic slope. 
Oxytropis lamberti, Hedysarum boreale, Lygodesmia 
juncea, Malvastrum coccineum, Solidago serotina were abun- 
dant in fields and waste places in the Deer Lodge Valley. 
On the Atlantic slope the following conspicuous weeds 
were observed: Cleome integrifolia, Grindelia squarrosa, 
Amaranthus retroflexus A, blitoides, Lactuca scariola, Iva 
xanthiifolia^ I. axillaris, and Malvastrum coccineum. 
