NATIVE WOODY PLANTS OF THE UNITED STATES 225 
Rhamnus rubra Greene. Eedstem buckthorn. 
Range: 4. 
Site: Well-drained, sun. 
Fruit: Drupe, available August-September. 
A small shrub ; flowers in June ; susceptibility to crown rust of oats not 
known. 
Hhamnus smithii Greene. Smith buckthorn. 
R. fasciculata Greene. 
Range: 11, 13, 14. 
Site: Well-drained, moist, sun. 
Fruit: Drupe. 
A small to large, dioecious, densely leafy shrub ; susceptible to the crown rust 
of oats. 
Ehamnus texensis, see Coluhrina texensis. 
Rhamnus tomentella, see Rhamnus calif ornlca. 
Rhamnus ursina, see Rhamnus califofmica. 
Rhapidophyllum hystrix (Fraser) Wendl. and Drude. Heedle palm. 
Ghamaerops hystrioo Fraser, Corypha hystrix (Fraser) Desf., Sahal hystrix 
Best. 
Range: 29, 30. 
Site : Dry, well-drained, sun. 
Fruit: Drupe. 
A small to large evergreen shrub ; rootstocks creeping and rooting. 
Rhododendron spp. 
This genus has often been divided into several separate genera or genus 
sections. The most notable for the United States are rhododendron and aaalea. 
It is generally agreed among botanists that these two cannot be maintained as 
separate genera although they may well appear to be separable as far as the 
species in this country are concerned. They are here treated as one. The 
species popularly known as azaleas are largely deciduous, at least in North 
America. Those known as rhododendrons are mostly evergreen. The azaleas 
are generally to be found growing in the sun ; the rhododendrons make their 
best growth in the shade. Nevertheless, there are no constant botanical char- 
acters to separate them. 
Rhododendron alabamense Rehd. 
Aisalea alabamense (Rehd.) Small. 
Range: 28, 29, 30. 
Site: Dry, well-drained, sun. 
Fruit: Capsule. 
A small shrub ; flowers April-May. 
Alabama azalea. 
Rhododendron albiflorum Hook. White-fiowered azalea. 
Azaleastrum albiflorum (Hook.) Rydb., Azalea alMflora Kuntze., Cladotham- 
nus campamilatus Greene. 
Range: 4, 12. 
Site : Well-drained, shade. 
Fruit: Capsule. 
A small to large shrub ; flowers June-July. While under normal range con- 
ditions it is not palatable to livestock, it is nevertheless poisonous. 
Rhododendron arborescens (Pursh) Torr. Smooth azalea. 
Azalea arborescens Pursh. 
Range: 27. 
Site : Well-drained, moist, sun, shade. 
Fruit: Capsule. 
A small to large shrub or rarely a small tree ; flowers June-July. 
Rhododendron atlanticum (Ashe) Rehd. 
Azalea atlantica Ashe. 
Range: 28, 29, 30. 
Site: Dry, well-drained, sun, half shade. 
Fruit: Capsule. 
A small shrub ; flowers April-May ; mat forming ; aggressive ; spreads by 
means of stolons; many often invade fields. 
