f smaller size, or of different shape
or character: then they are called BRACTS, and the flowers thus brought
together form a cluster. The kinds of flower-clusters of the
indeterminate class have received distinct names, according to their
form and disposition. They are principally _Raceme_, _Corymb_, _Umbel_,
_Spike_, _Head_, _Spadix_, _Catkin_, and _Panicle_.

203. In defining these it will be necessary to use some of the following
terms of descriptive botany which relate to inflorescence. If a flower
is stalkless, i. e. sits directly in the axil or other support, it is
said to be _sessile_. If raised on a naked stalk of its own (as in Fig.
199) it is _pedunculate_, and the stalk is a PEDUNCLE.

204. A peduncle on which a flower-cluster is raised is a _Common
peduncle_. That which supports each separate flower of the cluster is a
_Partial peduncle_, and is generally called a PEDICEL. The portion of
the general stalk along which flowers are disposed is called the _Axis
of inflorescence_, or, when covered with sessile flowers, the _Rhachis_
(back-bone), and sometimes the _Receptacle_. The leaves of a
flower-cluster generally are termed BRACTS. But when bracts of different
orders are to be distinguished, those on the common peduncle or axis,
and which have a flower in their axil, keep the name of _bracts_; and
those on the pedicels or partial flower-stalks, if any, that of
BRACTLETS or _Bracteoles_. The former is the preferable English name.

[Illustration: Fig. 200. A raceme, with a general peduncle (_p_),
pedicels (_p'_), bracts (_b_), and bractlets (_b'_). Plainly the bracts
here answer to the leaves in Fig. 199.]

205. =A Raceme= (Fig. 200) is that form of flower-cluster in which the
flowers, each on their own foot-stalk or pedicel, are arranged along the
sides of a common stalk or axis of inflorescence; as in the Lily of the
Valley, Currant, Barberry, one section of Cherry, etc. Each flower comes
from the axil of a small leaf, or bract, which, however, is often so
small that it might escape notice, and even sometimes (as in the Mustard
Family) disappears altogether. The lowest blossoms of a raceme are of
course the oldest, and therefore open first, and the order of blossoming
is _ascending_ from the bottom to the top. The summit, never being
stopped by a terminal flower, may go on to grow, and often does so (as
in the common Shepherd's Purse), producing lateral flowers one after
another for many weeks.

[Illust