LEAVES 19 
of two-ranked alternate leaves, while the Apple leaves 
are alternate without being two-ranked. Most leaves 
spread from the stem, but some are appressed, as in the 
Arbor-vite (Fig. 7). In this spe- 
cies the branches are two-ranked. 
Parts or Leaves.— A complete 
leat ~€£ consists of three parts: 
the blade, the thin expanded por- 
tion; the petiole, the leafstalk; 
and the stipules, a pair of small 
blades at the base of the petiole. 
The petiole is often very short 
and sometimes wanting. The 
stipules are often absent, and, even when present, they 
frequently fall off as soon as the leaves expand; some- 
times they are conspicuous. Most Willows show the 
stipules on the young luxuriant growths. 
VEINING.— The leaves of most 
trees have a distinct framework, 
the central line of which is called 
a midrib ; sometimes the leaf has 
several other lines about as thick 
as the midrib, which are called 
ribs ; the lines next in size, includ- 
ing all that are especially distinct, 
Fig. 8. are called veins, the most minute 
ones being called veinlets (Fig. 8). 
Kinps.— Leaves are simple when they have but one 
blade; compound when they have more than one. 
Compound 
vo 
in the Hickory. Pinnate leaves are of two kinds: odd- 
