618 EXOGENOUS AND ENDOGENOUS PLANTS. 



NyctaginacEyE. — Oxybaphus nyctaginea, (Torr.) Rocky river-banks. Upper Mississippi and St- 

 Peter's. Oxybaphus angustifolius, (Torr.) Sandy bluffs. St. Croix. Oxybaphus hirsutus (?), (Hook.) 

 Prairies. St. Peter's. 



Polygonace;e. Polygonum Pennsylvanicurn, (L.) Moist places. St. Croix. Polygonum Persicaria. 

 (L.) Moist places. St. Croix. Polygonum Hydropiper, (L.) "Water pepper. St. Croix. Polygonum 

 amphibium, (L.) July. Edges of shallow lakes. St. Croix. Polygonum aviculare, (L.) Door-weed. 

 Common. Polygonum articulatum, (L.) Joint-weed. Sandy barrens. St. Croix. Polygonum Vir- 

 ginianum, (L.) August. St. Croix. Polygonum arifolium, (L.) Ditches. Common. Polygonum 

 sagittifolium, (L.) With the preceding. Polygonum Convolvulus, (L.) Waste grounds. Polygonum 

 cilinode, (Michx.) Shores of Lake Superior. There is a singular variety of this species which runs 

 over the ground, its short axillary branches rooting at the extremity. Common to the steep bluffs of 

 Lake Superior, and the Alpine regions of Northern New York. Polygonum dumetorum, (L.) Moist 

 thickets. St. Croix. Rumex Hydrolapathum, (Hudson.) Wet, springy places. St. Croix. Rumex 

 crispus, (L.) Davenport, Iowa. Rumex Acetosella, (L.) La Pointe. Lake Superior. 

 Lauraceje. — Benzoin odoriferum, (Nees.) Southern Iowa. 

 Thymelace^e. — Dirca palustris, (L.) Moose-wood. St. Croix woods. 

 EljEAGINACE^e. — Shepherdia Canadensis, (Nutt.) Shore of Lake Superior. 

 Santalace^e. — Comandra umbellata, (Nutt.) Dry banks, Iowa and Minnesota. 

 Euphorbiace;e. — Euphorbia platyphylla, (L.) Dry fields. Davenport, Iowa. Euphorbia corollata, 

 (L.) Flowering spurge. Dry prairies of Iowa to St. Peter's. A striking feature of the prairie land- 

 scape, with its spreading umbel of minute flowers, continually put forth from June to September. It is 

 an emetic in common use among the Indians of the Northwest, attended frequently with fatal effects, from 

 the violence of its action. Euphorbia maculata, (L.) Falls of St. Croix. Euphorbia hypericifolia, (L.) 

 Waste dry places. St. Croix. Acalypha Virginica, (L.) Gravelly river-banks. Pilinophytum capita- 

 turn, (Kl.) August. Streets of Davenport, Iowa. Leaves aromatic. 



Juglandace/E. — Juglans nigra, (L.) Interior of Iowa. Juglans cinerea, (L.) Falls of St. Croix. 

 Carya alba, (Nutt.) Iowa. 



CuPULiFERyE. — Ostrya Virginica, (Willd.) Iron-wood. St. Croix. Carpinus Americana, (Michx.) 

 Falls of St. Croix. Corylus Americana, (Wait.) Hazelnut. Forming thickets on rich prairies, Iowa. 

 An index of a fruitful soil. Corylus rostrata, (Ait.) St. Peter's. Qucrcus. Several species. 



Myricace;E. — Myrica Gale, (L.) Bay berry. Moist margins of the Upper St. Croix. Comptonia 

 asplenifolia, (Ait.) Pine barrens and aspen thickets. Upper St. Croix. 



BetulacE/E. — Betula papyracea, (Ait.) Canoe birch. St. Croix and Lake Superior. Betula 

 pumila, (L.) Edges of bogs. St. Croix. Alnus incana, (Willd.) Springs and swamps. St. Croix. 



Salicace^e. — Salix Candida, (Willd.) Bogs. St. Croix. Salix longifolia, (Muhl.) Sandbar Willow. 

 Salix pedicellaris, (Pursh.) Swamps. St. Croix. Populus tremuloides, (Michx.) Aspen. Forming 

 close thickets. St. Peter's and St. Croix. Populus grandidentata, (Michx.) Iowa. 



Urticace^e. — Humulus Lupulus, (L.) Common hop. Native on all the tributaries of the Upper 

 Mississippi. Mr. Nuttall considers it a distinct species. Urtica gracilis, (Ait.) Falls of St. Croix. 

 Urtica Canadensis, (L.) Wooded banks of the St. Peter's. It is of this plant the Indians usually make 

 their fishing-lines; the rotted remains of the previous year's growth, furnishing an abundant extempora- 

 neous supply. Pilea pumila, (Gray.) Springy places. St. Croix. 



Conifers. — Pinus resinosa, (Soland.) Red pine. St. Croix. Pinus Strobus, (L.) White pine. 

 Tributaries of the Upper Mississippi, on the eastern side. Pinus Banksiana, (L.) Barrens. Upper 

 St. Croix. Abies Canadensis, (Michx.) Hemlock tree. Lake Superior. Abies nigra, (Michx.) Black 

 spruce. Lake Superior. Abies alba, (Michx.) Upper St. Croix. Larix Americana, (3Iichx.) Tame- 

 rack. Upper St. Croix. Thuya occidentalis, (L.) White cedar. Lake Superior. Juniperus Vir- 

 giniana, (L.) Red Cedar. Upper Mississippi. Taxus Canadensis, (Willd.) American yew. Upper 

 St. Croix and Lake Superior. 



ENDOGENS. 



AraceyE. — Arum triphyllum, (L.) May. Woods. Iowa and Minnesota. Calla palustris, (L.) 

 July. Bogs. St. Croix. Symplocarpus fcetidus, (Salisb.) Skunk cabbage. Swamps. Iowa. Not 



