ROSACEAE. 105 
Aronia. Chokeberry. 
(Family Rosaceae). 
Shrubs: deciduous. Twigs mod- 
erate, roundish, glabrous, brown: 
pith moderate, rounded, pale, con- 
tinuous. Buds solitary, sessile, ob- 
long, flattened and appressed, with 
about 5 often abruptly = short- 
pointed more or less glandular- 
denticulate scales. Leaf-scars al- 
ternate, U-shaped, low: bundle- 
traces 3: stipule-scars lacking. 
(Pyrus). 
Aronia, like Sorbus, is segre- 
gated from Pyrus by the less con- 
servative botanists and retained in 
that genus by those who are more 
conservative. In common with 
the firethorn and several other 
diverse types, it has found lodg- 
ment at one time or other in the 
genus Mespilus, now by common 
consent restricted to the German 
medlar, M. germanica. The only winter-character reference, 
to A. arbutifolia, is Schneider’s f. 147. 
In curious contrast with the absence of apple-pear hy- 
brids, several crosses are known to occur between mountain- 
ash (Sorbus) and chokeberry (Aronia) variously considered 
to be distinct genera or sections of Pyrus: for these the 
generic name x Sorbaronia may be used appropriately. 
1. Twigs and buds glabrous. 
(Black chokeberry). (1). A. melanocarpa. 
Twigs more or less woolly. 2. 
2. Buds quickly glabrous. (Purple c.) A. atropurpurea. 
-Buds somewhat woolly. (Red chokeberry). A. arbutifolia. 
