38 
NATURE STUDY. 
infallible guide and once familiar with them one need make no 
mistake in attempting to recognize the sumacs. 
Leaf No. i in the cut represents both the staghorn and shiny 
sumac. The leaflets vary from eleven to thirty-one in number 
and are sharply serrate. The shrubs may be distinguished by 
the downy or pubescent twigs on the former and the smooth 
branches of the latter. The dwarf sumac leaf is No. 2. The 
leaflets are fewer than those of the former two and the margins 
are entire. The most noticeable feature is the winged rachis 
already mentioned. The entire margin distinguishes it from 
the preceding two ; the winged rachis shows that it is not No. 
3, which is poison sumac. When you see entire leaflets and 
narrow rachis, Beware ! 
No. 4 with its three leaflets would hardly be recognized as a 
sumac. In fact no one but a botanist who studies the flowers 
and fruit calls it so. He knows it as Rhus toxicodendron. From 
its climbing habit it is called poison ivy. When it has nothing 
to climb it becomes rigid and stands erect. By some it is 
known as poison oak. Indeed, when it grows erect and bears 
leaves with short lobes as it sometimes does, it somewhat re¬ 
sembles a small, shrubby oak. Like many a human outlaw it 
assumes various characters but should be looked upon with 
suspicion in all. It is fond of clinging to the trunk of a tree, 
ascending to the branches and forming a very pretty covering 
for the gray bark. It climbs up a fence post or clambers over 
a wall, sending up a crown of foliage above its support. When 
there is no support and the ground is moist the stem lies on the 
surface from which the leaves rise, sometimes so abundantly as 
to conceal everything beneath them. 
It is sometimes confounded with woodbine or Virginia creep¬ 
er, a beautiful and harmless vine. This invariable difference 
should prevent any one from erring. The poison ivy has three 
leaflets, the woodbine five. This distinction has added two 
more lines to the above quoted jingle. 
“Leaves three, 
Quickly flee.” 
