610 EXOGENOUS PLANTS. 
parviflorum, (Nutt.) July Ist. Crevices of the exposed granite and quartzite rocks, Upper St. Peter’s, 
associated with Lycopodium rupestre and Woodsia Ilvensis; differing from the more common T. tereti- 
folium, in the characters specified by Nuttall, but still doubtful as a distinct species. Claytonia Virgi- 
nica, (L.) April. Rich hillsides. 
Matvacez.—Abutilon Avicenne, (Gaertn.) July. Yards and roadsides, abundantly naturalized 
about western towns. 
a —Linum rigidum, (Pursh.) July. “Yellow flax.” High prairies of Iowa. 
GERANIACEH.—Geranium maculatum, (L.) May. Copses and fields. Geranium Carolinianum, (L.) 
May. Waste places, Iowa. Geranium Robertianum, (L.) August. Shady crevices of trap-rocks, Falls 
of St. Croix. 
OxaLipaAcea.—Oxalis Acetosella, (L.) ‘ Wood-sorrel.” Rooting in moss, in deep woods, Lake Supe- 
rior. Orxalis violacese, (L.) May. Dry banks, Iowa. Oxalis stricta, (L.) Waste places. 
BALSAMINACEZ.—Impatiens pallida, (Nutt.) August. Springy places, St. Croix. Impatiens fulva, 
(Nutt.) With the preceding. 
ZANTHOXYLACEX.—Zanthoxylum Americanum, (Mill.) April. “Prickly ash.” Forming trouble- 
some thickets on river-banks throughout the Northwest. Ptelia trifoliata, (L.) June. Dry river-banks. 
Called ‘“ water-ash,” from the siagalar appearance of its fruit. 
ANAcARDracEa. —Rhus typhina, (L.) June. St. Croix. Rhus glabra, (L.) The most common 
species of sumac. The milky juice from the Jeealunes branches affords an indelible ink. Rhus Toxico- 
dendron, (.) “ Poison-ivy.” Very abundant on all river-banks, thickets, &c. Rhus venenata, (D. C.) 
“ Poison-ash.”” Deep, swampy woods, St. Croix. Rhus aromatica, (Ait.) June. Sandy shore of Red 
Cedar River, Iowa. 
ACERACES.—Acer spicatum, (Lam.) Upper St. Croix and Lake Superior. Acer saccharinum, (L.) 
Interior of Iowa, Upper St. Croix, &e. Acer dasycarpum, (Ehr.) Alluvial river-bottoms throughout 
the Northwest. Acer rubrum, (L.) Falls of St. Croix. Negundo aceroides, (Meench.) River-bottoms, 
Towa. 
CELASTRACEH.—Staphylea trifolia, (L.) May. Thickets, Iowa. Celastrus scandens, (L.) This 
common vine abundantly found in thickets, and along banks of streams, throughout the Northern States, 
popularly known by the name of “Staff-tree,” or “Climbing Bitter-swect,” is frequently resorted to by 
the Indians of the Northwest, in times of scarcity, as an article of food. The vine itself, cut into pieces 
of a convenient size, is boiled till the thick bark acquires a pulpy consistence, and the water becomes 
impregnated with mucilage. The woody part being rejected, the rest is eaten. By the Chippewa In- 
dians it is called Bi-ma-quat. Euonymus atropurpureus, (Jacq.) June. Blue Earth River, and banks 
of the Mississippi. Showy in the frequent abundance of its scarlet fruit in winter. The root has also 
attained note in some quarters as a medicinal agent. 
RaAMNACEH.—Rhamnus alnifolius, (L’Hen.) May. Alder swamps of the St. Croix River. Rham- 
nus longifolius, (Pursh.) Banks of the Mississippi, near Davenport, Iowa. Ceanothus Americanus, (L.) 
July. “Red root.” A shrubby plant, well known on the Iowa prairies as a troublesome obstacle, by 
‘its tough roots in first breaking the soil. Ceanothus ovalis, (Bigelow.) May. Interior counties of 
Towa, and on dry sandy ridges of the St. Croix; in the latter locality seeming to take the place of the 
preceding species, and an indication of a more barren soil. 
ViTacE&.—Vitis riparia, (Michx.) ‘ River-side Frost-grape :” the only northwestern species. Am- 
eae quinquefolia, (Michx.) June. River-banks. 
ALACE.—Polygala purpurea, (Nutt.) July. Wet and rather barren places, Towa and 
StS Polygala incarnata, (L.) Dry soil, interior of Iowa. Polygala cruciata, (L.) July 28th. 
Moist margins of swampy lakes, St. Croix. Polygala verticillata, (L.) Dry hills, Iowa. Polygala 
senega, (L.) ‘Seneca snake-root.” Polygala polygama, (Walt.) July. Sandy soil, St. Croix. Poly- 
gala paucifolia, (Willd.) Long Portage Trail from Lake Superior to the Upper St. Croix. 
_ Lecuminosa.—Lathyrus maritimus, (Bigelow.) ‘‘ Beach-pea.” Common. to the sandy shore of 
Lake Superior, and the Atlantic sea-beach. Lathyrus venosus, (L.) June. Copses. St. Peter’s. La- 
thyrus ochroleucus, (Hook.) May. St. Croix and St. Peter’s. Lathyrus palustris, (L.) Moist river- 
banks, St. Peter's. Phaseolus diversifolius, (Pers.) August. ‘Wild bean.” Gravelly*banks of the 
Mississippi, Davenport, Iowa. Apios tuberosa, (Meench.) August. The root of this common plant, 
abundantly seattered on the banks of streams, and alluvial bottoms throughout the United States, is the 
