EXOGENOUS PLANTS. 



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true " Pomrue de Terre" of the French voyageurs, and the " Mdo," or wild potato of the Sioux Indians. 

 By the latter name it is extensively used as an article of diet. It grows in great abundance, and of su- 

 perior quality, on the banks of the St. Peter's. When properly cooked, it is by no means unpalatable. 

 Amphicarpaea monoica, (Nutt.) August. Rich woods, bearing underground pods, like the peanut of 

 commerce. Desmodium nudiflorum, (D. C.) August. Woods, St. Croix. Desmodium acuminatum, 

 (D. C.) August. St. Croix. Desmodium Canadense, (D. C.) July. Moist banks of streams. Les- 

 pidezacapitata, (Michx.) August. Dry prairies, Iowa and Minnesota. Astragalus caryocarpus, (Ker.) 

 May. Gravelly ridges in the interior of Iowa, Fort Snelling, at the junction of the Mississippi and St. 

 Peter's Rivers, and abundant on the latter stream, being a characteristic plant of the peculiar drift de- 

 posit of that region. The fruit, which is a pod, closely resembles a plum in external appearance, from 

 which fact it has received the common name of "ground-plum." The thick fleshy exterior is highly 

 charged with moisture, having the usual taste of the pea tribe, and is frequently used to allay the thirst 

 of the traveller on the great western plains. Astragalus Canadensis, (L.) July. Banks of the Missis- 

 sippi and St. Peter's Rivers. Oxytropis Lamberti, (Pursh.) June. Upper St. Peter's, on drift ridges- 

 Glycyrrhiza lepidota, (Nutt.) June. "Wild liquorice." Banks of the Blue Earth, St. Peter's, and St. 

 Croix Rivers. Possessing some of the sensible qualities of the commercial liquorice, without its sweet- 

 ness. Tephrosia Virginiana, (Pers.) July. Sandy soil, Davenport, Iowa. Amorpha fructicosa, (L.) 

 May. A handsome shrub, edging river-banks throughout the Northwest. Amorpha nana, (Nutt.) June 

 18th. High prairies on Blue Earth River. A characteristic plant of woodless, grassy hills on the Mis- 

 souri, often diffused, as Mr. Nuttall remarks, " like heath in Europe, over many acres in succession, and 

 is the only upland shrub apparently capable of withstanding the peculiarities of this climate." (Nutt., 

 Genera, vol. ii. p. 91.) Amorpha canescens, (Nutt.) July. This is the noted "lead-plant" of Iowa 

 and Wisconsin. Its value as a mineral indication may probably be summed up in this. It attaches itself 

 with most luxuriance to rocky crevices and spots about which the peculiar dry earth, indicating a mineral 

 vein, exists, and the miner is thus guided in making his excavations. Farther than this any definite 

 relation with the lead-bearing rock is sufficiently disproved by the extensive geographical range of this 

 plant, from British America to Texas. Psoralea argophylla, (Pursh.) July. High prairies in Iowa and 

 Minnesota. A characteristic plant, with silvery foliage. Psoralea esculenta, (Pursh.) June 3d. Gravelly 

 ridges of the St. Peter's. This is the valuable plant known as the " Indian turnip," — " Pomme de Prairie," 

 of the French voyageurs; "Tipsinah" of the Sioux Indians. It occurs over a wide range of country be- 

 tween the Mississippi and the Rocky Mountains, and is a characteristic plant of the " Coteau des Prairies." 

 The root, frequently attaining the size of a hen's egg, is of a regular, cylindric, ovoid shape, consisting 

 of a thick leathery envelope, easily separating when fresh from its smooth internal part. The latter is of 

 friable texture, except towards the axis, where some ligneous fibres are intermixed. When dry, it acquires 

 a sweetish taste, and is easily pulverized, affording a light, starchy flour, suitable for all the uses of the 

 ordinary article. When growing its aspect is that of a Lupine. It selects a dry, gravelly, but not 

 barren soil, and is well worthy the attention of cultivators, as an interesting production of the North- 

 west. Petalostemon violaceum, (Michx.) June. Dry hills throughout the Northwest. Petalostemon 

 candidum, (3Iichx.) August. Dry prairies. Petalostemon villosum, (Nutt.) Sandy banks. "Tra- 

 verse des Sioux," Falls of St. Anthony, Barrens of St. Croix. A very elegant species in flower and foliage. 

 Trifolium reflexum, (L.) June. Buffalo clover. Low grounds. Iowa. Trifolium repens, (L.) St. 

 Peter's and St. Croix. Lupinus perennis, (L.) St. Croix Barrens. Baptisia leucantha, (Torr. & Gr.) 

 July. Rich soil, Davenport and St. Croix. Baptisia leucophcea, (Nutt.) May. Dry prairies. Iowa. 

 Cercis Canadensis, (L.) April. " Red-bud." Banks of the Mississippi. Davenport and Rock Island. 

 Cassia chamcecrista, (L.) July. Sensitive pea. Sandy soil. Iowa. 



Rosacea. — Prunus Americana, (Marsh.) Wild plum. Forming thickets. Mississippi and St. Croix. 

 Generally producing an abundance of fruit. Cerassus pumila, (Michx.) Sand-cherry. Sandy banks of 

 Lake St. Croix. Beach of Lake Superior. Cerassus Pennsylvanica, (Loisel.) Bird cherry. St. Croix. 

 Cerassus Virginiana, (D. C.) Choke cherry. St. Croix. Spiraea opulifolia, (L.) June. Rocky river 

 banks, Iowa. Spiraea salicifolia, (L.) July. Wet places. St. Peter's and St. Croix. Spiraea tomen- 

 tosa, (L.) July. Margins of lakes. Minnesota. Agrimonia Eupatoria, (L.) August. Waste places. 

 St. Croix. Geum Virginianum, (L.) June. Shady hills. St. Peter's. Geum striatum, (Ait.) Moist 

 places. St. Peter's. Geum triflorum, (Pursh.) May. Head of Lake St, Croix, Fort Snelling, and St. 

 Peter's. This fine species, particularly beautiful in its plumed fruit, is well worthy to usurp the place of 



