14 Bulletin of the University of Texas 
shoots in the axils of leaves, or at the end of the main axis of the 
shoot. Flowers which occur in clusters may be grouped for 
convenience into a number of definite types. A raceme of flowers 
or fruits is an arrangement of the individual flowers on the 
more or less elongated axis, each with a separate pedicel, all 
about equal in leneth. <A panicle is a flower cluster in which 
the simple pedicels of the raceme become branched and spreading. 
A corymb is also like the raceme, but in this ease the flower shoot 
is Shortened, and the lower pedicels are longer than those borne 
above them, so that the clusters become flat topped with all the 
flowers borne at about the same level. A cyme resembles a corymb, 
but in this case the pedicels become branched and the central 
flower blooms first. An.wmbel is a flower cluster in which the 
pedicels of the flowers start from the same point and become about 
of equal length. A head is a cluster in which the axis is very 
short and the flowers are without pedicels, or nearly so, forming 
a globose or compressed cluster. A catkin, or ament, is a long, 
slender, drooping axis which bears numerous solitary sessil 
flowers in the axils of bracts, the whole cluster falling away after 
the maturity of the flowers. Among trees, the willows, poplars, 
oaks, and birches bear their flowers in catkins. 
A flower has been defined as the forerunner of a seed; but 
plants bear their seeds in some kind of a structure known as a 
fruit, consisting of the ripened ovary, and sometimes other ac- 
eessory parts. The fruit is a structure which aids in the distri- 
bution of seeds. Fruits are either dry or fleshy. Dry fruits may 
be grouped under two heads: those which open and shed their 
seeds at maturity are dehiscent, those which do not open are inde- 
hiscent. Of the indehiscent fruits, our commonest examples 
among the trees are the samara or the dry winged fruits of 
maples, elms, ash, ailanthus, hop tree, ete.; the acorn of the oaks; 
the nut of the walnut and hickory. The dry dehiscent fruits are 
known as pods if the seeds are fastened along one side and there 
is but a single cavity, otherwise they are called capsules. 
Among the fleshy fruits our commonest examples are the berry, 
pome, and drupe. The term berry may be used to denote all 
fleshy fruits with more than one seed buried in the mass of pulp. 
The pome or apple fruit differs from the berry by bearing the 
seeds inclosed by a hardened substance. The drupe is a single- 
seeded fleshy fruit. 
