THE COLUMBIAN EXPOSITION. 455 



Potamogeton. Any of our numerous species. Pondweed. 

 Ranunculus aquatilis, Ix, and its varieties. Water-crowfoot. 



" multifulus, Pursh. Water-crowfoot. 



Sagittaria variabilis, Engelm. Arrow-head. 

 Spirodela polyrrlnza, Schleid. Duckweed. 

 Spirogyra. Several species. Pond Scum. 

 Vallisneria spiralis, L. Eel-grass. 

 Vaucheria. Several species of green pond weeds. 

 Wolffia brasiliensis, Weddell. 

 " Columbiana, Karsten. 

 Zizania aquatica, Li Wild Rice. 



NATIVE TREE-LIKE OR LARGE SHRUBS. 



Acer spicatum, Lam. Mountain Maple. 



Alnus incana, Willd. Speckled Alder. Hoary Alder. Black Alder. 



•' serrulata, Willd. Smooth Alder. Black Alder. 

 Asiniina triloba, Dunal. Papaw. Custard Apple. 

 Cercis canadensis, L. Red-bud. Judas-tree. 

 Cornus alternifolia, L. f. Dogwood. 

 " circinata, L'Her. Dogwood. 

 Cratcegus coccinea, L. Scarlet Hawthorn. Jled Hawthorn. White Thorn. 

 " crus-galli, L. Cockspur Thorn. Newcastle Thorn. 

 " tomentosa, L. Black Thorn. Pear Haw. 

 Euonymus atropurpurens, Jacq. Burning-bush. Waahoo. Spindle-tree. Arrow-wood. 

 Hamamelis virginica, L. Witch-hazel. 

 Primus americana, Marshall. Wild Plum. Canada Plum. Horse Plum. 



" virginiana, L. Choke-cherry. 

 Ptelea trifoliata, L. Hop- tree. Shrubby Trefoil. Wafer Ash. 

 Querctis prinoides, Willd. Chinquepin Oak. 

 Rhus copallina, L. Dwarf Sumach. 

 " glabra, L. Smooth Sumach. 

 " typhina, L. Staghorn Sumach. 

 " venenata, DC. Poison Sumach. Poison Dogwood. 

 Salix discolor, Muhl. Glaucous Willow. 

 " longifolia, Muhl. Sand-bar Willow. 

 " lucida, Muhl. Shining Willow. 

 Sambucus canadensis, L. Common Elder. 



" racemosa, L. Red-berried Elder. 



Staphylea trifolia, L. Bladder-nut. 

 Vibu7'num lentago, L. Sheep-berry. Nanny-berry. 



" prunifolium, L. Black Haw. Stag-bush. 



Xanthoxylum americanum. Mill. Prickly Ash. Toothache-tree. 



FLOWERING PARASITES AND SAPROPHYTES DESTITUTE OF GREEN LEAVES. 



Aphyllon fasiculatum. Gray. Cancer-root. 



'• uniflorum, Gray. Cancer-root. 



Conopholis americana, Wallroth. Squaw-root. 

 Cuscuta chlorocarpa, Engelm. Dodder. 



•' gronovii, Willd. Dodder. 



" tenuiflora, Engelm. Dodder. 

 Epiphegus virginiana, Bart. Beech-drops. 

 Monotropa hypopitys, L. Pine-sap. False Beech-drops. 



" uniflora, L. Indian Pipe. Corpse-plant. 



Pterospora andromedea, Nutt. Pine-drops. 



GREEN-LEAVED PARASITES. 



Castilleia coccinea, Spreng. Scarlet Painted-cup. 



" pallida. Kunth, var., septentrionalis, Gray. Pale Painted-cup. 

 Comandra livida, Richardson. Bastard Toad-flax. 



" umbellata, Nutt. Bastard Toad-flax. 



