Feb., 1905.] Key— Ohio Sumacs in Winter Condition. 



293 



The following named plants, found in Ohio, produce hiber- 

 nacula : 



Lemna cj'clostasa (Ell.) Che v. 

 Lemna minor L. 

 Lemna triuslca L. 

 Spirodela polyrhiza(L.) Schleid. 

 Wolffia Columbiana Karst. 

 Wolffia punctata Gris. 

 Philotria canadensis (Mx.) Britt. 

 Zannichellia palustris L. 

 Potomageton pusillus L. 

 Potomageton lonchitis Tuckcrm. 

 Potomageton pusillus polyphyllus 

 Morong. 



Potomageton zostera?folius Schum. 

 Potomageton friesii Ruprecht. 

 Potomageton vaseyi Robbins. 

 Utricularia cornuta Mx. 

 Utricularia gibba L. 

 Utricularia intermedia Hayne. 

 Utricularia vulgaris L. 

 Myriophyllum heterophyllus Mx. 

 Myriophyllum spicatum L. 

 Myriophyllum tenellum Bigel. 

 Myriophyllum verticillatvim L. 



KEY TO THE OHIO SUMACS IN THE WINTER CONDITION. 



Mabel Schaffxer. 



Rlius L. Small trees, shrubs, or woody vines climbing by 

 rootlets, with a milky or acrid resinous sap ; pith more or less 

 cylindrical, often large, white, brown, or yellowish; leaf scars 

 alternate, not two-ranked; bundle scars several; stipular scars 

 none; terminal bud present or absent; axillary buds single, not 

 clustered at the tip of the twig, sometimes surrounded Ijy or hid- 

 den under the leaf scar; bud scales several; sap of some species 

 poisonous to most people when touched. 



1. Leaf scar surrounding the axillary bud; pith very large, brown; 



erect shrubs or small trees. 2. 

 1. Leaf scar not completely surrounding the axillary bud; pith medium; 



erect shrubs, small trees, or woody vines climbing by rootlets. 3. 



1. Leaf scar on the short petiole base which covers the axillary bud; pith 



small; bark glabrous, aromatic; low, ascending or diffuse shrub. 



R. aromatica Ait. Fragrant vSumac. 



2. Twigs glabrous, somewhat glaucous. R. glabra L. Smooth Sumac. 



2. Twigs velvety-hairy. R. liirta (L.) Sudw. Staghorn Sumac. 



3. Bark velvety pubescent, brown; buds short, rounded; erect shrub or 



small tree. R. copallina L. Dwarf Sumac. 



3. Bark glabrous or nearly so, or if pubescent then with aerial rootlets, 



gray or brownish-gray; buds projecting; bark and wood poisonous 

 to most people when touched. 4. 



4. Leaf scars heart-shaped; bundle scars numerous, scattered; erect 



shrub or small tree in swamps. R. vcrnix L., Poison Sumac. 



4. Leaf scars LT-shaped; bundle scars numerous, scattered or arranged 

 in a curve; woody vine climljing by aerial rootlets, sometimes 

 shrubby or tree-like. R. radicaus L. Poison Ivy. 



