DEFINITIONS OF TERMS 1F 
onion, garlic, etc., and those where the scales are thick and narrow are 
called scaly bulbs. 
As to the arrangement of branches and leaves, they are opposite when 
two.are borne at the same node from opposite sides of the stem; whorled 
or verticillate when three or more are borne at the same node, arranged 
regularly around the stem; fascicled or fasciculate when two or more 
are borne at the same node on the same side of the stem; alternate when 
one is borne at each node on one side, and the next above or below on 
the opposite side of the stem; distichous when regularly arranged one 
above another in two opposite rows; and secwnd when all are turned 
toward one side. 
THE LEAVES.—A typical complete leaf consists of the blade or lamina, 
the broad thin part of ordinary leaves, the petiole or leaf-stalk, and a 
pair of stipules, variously shaped appendages at the base of the leaf-stalk 
or at the nodes, which may be leaf-like, scale-like, or even represented 
by sheaths or by spines. Stipules are frequently wanting, such plants 
being then termed exstipulate. The end by which the leaf, or any other 
part of a plant is attached, is called the base; the opposite or free end, 
the apex. 
The petiole or leaf-stalk is frequently wanting, the leaves being then 
called sessile. When the leaf-base clasps the stem it is called amplexicaul 
or stem-clasping; when the lobes meet around the stem so that the blade 
appears as though it were pierced by the stem, it is called perfoliate; 
when the edges of the leaf extend downward along the stem as ridges 
or wings it is called decurrent; when the base of the blade or the petiole 
forms a more or less closed vertical cylinder surrounding the stem, it is 
called sheathing. 
When the leaves are inserted on a stem or branch, they are termed 
cauline; when they or the flowers are borne on the roots or rhizomes or 
very close to the base of the stem, they are termed radical. Radical 
leaves that spread in a circle on the ground forming a rosette are called 
rosulate. 
Leaves are composed of a framework, consisting of ribs and veins, 
and of the softer tissue. When there is only one main vein much 
stronger than the others it is called the midrib; the primary divisions 
on each side are called the lateral veins or nerves, and the ultimate 
divisions the veinlets, or nervules. In cases where several equally strong 
veins radiate from the top of the petiole, they are termed palmately, or 
digitately nerved or veined, or in peltate leaves radiately nerved. In 
palmately nerved leaves, where the veins all start from the base, they 
are called 3-nerved, 5-nerved, etc., according to the number of nerves, 
but when some start just above the base they are called 3-plinerved, 
5-plinerved, ete. 
Venation is the term applied to the method of arrangement of the 
veins; there are two principal kinds, parallel-veined and netted-veined 
or reticulate. In parallel-veined leaves the whole frame work consists of 
slender ribs or veins that run parallel to each other, either from the 
base to the apex, or from the midrib to the margins, not dividing and 
subdividing and forming meshes. In netted-veined or reticulate leaves 
the veins branch and rebranch into finer and finer veinlets which unite 
with each other to form meshes; this network of veins is usually spoken 
of as the reticulations. Sometimes the nerves are so obscured by other 
