March, 1905.] Key, Ohio Maples in Winter Condition. 297 



4. Those found on rocks either hmestone or sandstone are: 



Polypodium vulgare. Asplenium niontanum. 

 polypodioides. " parvuluni. 



Pelkea atropurpurea. Camptosorus rhizophyllus. 



Asplenium pinnatifidum. Filix bulbifera. 



ebenoides. Woodsia ilvensis. 



■ " trichomanes. Selaginella rupestris. 



" ruta-muraria. 



5. A very few may be found growing in sandy soil. Among 



these we find: 



Equisetum arvense. Equisetvim sylvaticum. 



pratense. 



6. The following are found growing under varying conditions 



in manv localities: 



Botrychium obliquum. Dennstsedtia punctilobula. 



dissectum. • Dryopteris thelypteris. 



" lunaria. Polystichum acrostichoides. 



" virginianum. Asplenium angustifolium. 



Onoclea sensibilis. Pteridiuin aquilinum. 



Matteucia struthiopteris. 



7. In addition to what has been mentioned above, Osmunda 

 regalis is occasionally found in standing water, and Azolla 

 caroliniana floating on still water. 



KEY TO THE OHIO MAPLES IN THE WINTER CONDITION. 



Charles H. Flory. 



Acer, L. Trees or shrubs with fibrous roots; twigs slender or 

 sometimes robust, usually glabrous, green, gray, brown or red, with 

 or without lenticular corky ridges ; lenticels sometimes prominent ; 

 pith solid, rather small; leaf scars opposite, contiguous or con- 

 nected by a ridge, sometimes meeting in a free point, either U or 

 V shaped ; stipular scars none ; bundle scars 3-5 ; buds short- 

 stalked or sessile; terminal bud present; lateral buds prominent, 

 often three side by side; scales either dry or fleshy, glabrous or 

 pubescent, brown, gray, green or red; bark close or exfoliating, 

 gray, brown or black; wood light colored, usually hard, heavy, 

 strong, stiff and tough, of fine texture or frequently wavy 

 grained; fruit a 2-winged, 2- seeded samara. 



1. Twigs green or purplish green, glaucous; axillary buds originally cov- 

 ered by the petioles; buds hairy, not stalked; leaf scars meeting in 

 a free point. Acer negundo L Boxelder. 



1. Twigs green, brownish, or reddish, with narrow, white, longitudinal 

 lines; buds large, glabrous, stalked; a shrub or small tree. 



Acer peiinsylvanicmn L. Striped Maple. 



1. Axillary buds not covered by the petiole base; twigs not striped. 2. 



2. Older twigs with prominent, longitudinal, corky ridges; cultivated, 



from Europe. Acer campestrc L. English Maple. 



2. Twigs without corky ridges. 3. 



