OUTLINES OF BOTANY. XXlll 
that is to say, the portion of the flowering branch from the last stem-leaf 
to the flower, or to the first ramification of the inflorescence, or even up to 
its last ramifications; but the portion extending from the first to the last 
ramification or the axis of inflorescence is often distinguished under the 
name of rachis. 
69, A Scape or radical Pedunele isa leafless peduncle proceeding from the 
stock, or from near the base of the stem, or apparently from the root itself. 
70. A Pedicel is the last branch of an inflorescence, supporting a single 
flower. 
71. The branches of inflorescences may be like those of stems, opposite, 
alternate, etc. (32, 33), but very often their arrangement is different from 
that of the leafy branches of the same plant. 
72. Inflorescence is 
centrifugal, when the terminal flower opens first, and those on the 
lateral branches are successively developed. 
centripetal, when the lowest flowers open first, and the main stem 
continues to elongate, developing fresh flowers. 
73. Determinate inflorescence is usually centrifugal. Intermediate in- 
florescence is always centripetal. Both inflorescences may be combined on 
one plant, for it often happens that the main branches of an inflorescence 
are centripetal, whilst the flowers on the lateral branches are centrifugal ; 
or vice versa. 
74, An Inflorescence is 
a Spike, or spicate, when the flowers are sessile along a simple undi- 
vided axis or rachis. ; 
a, Raceme, or racemose, when the flowers are borne on pedicels along 
a single undivided axis or rachis. 
a Panicle, or paniculate, when the axis is divided into branches bear- 
ing two or more flowers. 
a Head, or capitate, when several sessile or nearly sessile flowers are 
collected into a compact head-like cluster. The short, flat, convex or 
conical axis on which the flowers are seated, is called the Receptacle, a term 
also used for the torus of a single flower (135). The very compact flower- 
heads of Composite are often termed compound flowers. 
an Umbel, or wmbellate, when several branches or pedicels appear to 
start from the same point and are nearly of the same length. It differs 
from the head, like the raceme from the spike, in that the flowers are not 
sessile. An umbel is said to be szmple, when each of its branches or rays 
bears a single flower; compound, when each ray bears a partial umbel or 
wmbellule. 
a Corymb, or corymbose, when the branches and pedicels, although 
starting from different points, all attain the same level, the lower ones 
being much longer than the upper. It is a flat-topped or /fastigiate 
anicle. 
f a Cyme, or cymose, when branched and centrifugal. It is a centrifu- 
gal panicle, and is often corymbose. The central flower opens first. The 
lateral branches successively developed are usually forked or opposite 
{dichotomous or trichotomous), but sometimes after the first forking the 
branches are no longer divided, but produce a succession of pedicels on 
their upper side forming apparently unilateral centripetal racemes ; whereas, 
if attentively examined, it will be found that each pedicel is at first ter- 
minal, but becomes lateral by the development of one outer branch only, 
