CLETHRA 163 



2. C. acuminata Michx. White- Alder . A shrub or small tree 

 to 6 m. high, with upright or spreading branches; twigs slender; 

 buds tomentulose, the terminal 5 mm. long; fruit a persistent ovoid 

 nodding capsule, 5 mm. long. Woods, in the mountains. West Vir- 

 ginia to Georgia and Tennessee (Fig. 240). 



LEDUM L. (Ericaceae) 



Evergreen bog shrubs. Twigs rather slender, rounded; pith 

 small, somewhat 3 -sided, spongy, brownish. Buds solitary, ses- 

 sile, somewhat compress 3d, small, with about 3 exposed scales; 

 the terminal inflorescence buds large, round or ovoid, with about 

 10 broad glandular-dotted scales. Leaves alternate, simple, en- 

 tire, elliptical or oblong. Leaf-scars half- elliptical or cordate, 

 the lowest linear; bundle-trace 1; stipule-scars lacking. 



1. L. groenlandicum Oeder. Labrador-Tea. Erect shrub, 

 1 m. or less high; leaves evergreen, oblong or linear-oblong, 

 entire, revolute, clothed with rusty wool underneath, 2-5 cm. long. 

 Bogs and acid soil, Greenland to Alaska, south to Pennsylvania, 

 Wisconsin, Minnesota, Alberta and Washington (Fig. 241). 



RHODODENDRON L. * (Ericaceae) 



Evergreen or deciduous shrubs or small trees. Twigs terete; 

 pith small, roundish, continuous. Buds solitary, sessile, the 

 upper ovoid with 6 or more ciliate scales and the flower-buds usu- 

 ally much enlarged, the lower successively smaller. Leaf-scars 

 alternate, shield-shaped or the lowest linear; bundle-trace 1 or 

 3 or many; stipule-scars none. Fruit a dry capsule, often present 

 in winter. The deciduous species have been placed by some authors 

 in the genus Azalea L. 



a. Leaves evergreen 



b. Leaves elongate-oblanceolate, the 



base acute l.R. maximum 



b. Leaves broadly elliptical, the 



base rounded 2.R. catawbiense 



a. Leaves deciduous 



b. Buds essentially glabrous 



c. Twigs entirely glabrous 8.R. arborescens 



c. Twigs usually bearing sparse 

 long hairs 

 *Mr. E. L. Manigaulthas assisted materially in the preparation of 

 this key. 



