RUTACEAE. ; 169 
Poncrrus. Hardy Orange. 
(Family Rutaceae). 
Shrubs with branch-spines: de- 
ciduous. Twigs triangular, di- 
lated into the thorns at the nodes, 
rather stout: pith rather large, 
white, homogeneous. Buds rather 
small, solitary, sessile, subglobose, 
with about 3 exposed scales, the 
end-bud absent. lLeaf-scars very 
small, alternate, 5-ranked, half- 
elliptical, scarcely raised: bundle- 
trace 1, crescent-shaped, evanes- 
cent: stipule-scars lacking. (Aegle, 
Citrus). 
The hardy orange, capable of 
growth even in the North as an 
effective and attractive hedge- 
plant, presents another instance 
of the occasional occurrence of 
hybridization between different 
genera, and at the same time em- 
phasizes the closeness of the re- 
lationship of such genera. Poncirus gives hybrids, more or 
less intermediate in character, with the grape fruit belonging 
to the evergreen unifoliolate genus for which the name Citrus 
is now reserved; but it has been considered itself to belong 
to that genus by botanists for whom generic characters might 
be drawn a little more broadly than they are under the pre- 
vailing custom. Its winter-characters are pictured by Schnei- 
der, f. 85. 
For the hybrid “citranges” the generic name X Ponciro- 
citrus might find appropriate use. 
Twigs glabrous, glossy green: buds glabrous, blood-red. 
P. trifoliata. 
