78 
INFLOEESCENCE. 
Fig. 92. 
the flower. Fig. 91 (Lamium, of the family Labiatge) repre- 
sents a verticillaster, or whorl. A circle of flowers produced 
at the axils of leaves, was formerly termed a whorl ; but as the 
central flowers are found to expand first, or to be centrifugal, 
this mode of inflorescence is now considered as cymose^ the 
flowers being sessile, or nearly so, and the clusters are called 
verUcillasters. Yet as the term whorl or wliorled has been by 
former botanists used in descriptions of plants, we shall retain 
the same in its usual acceptation. 
Raceme (Fig. 92, d) consists of numerous 
flowers or pedicels, and all arranged on one 
common peduncle, as in the locust and currant. 
The only difference between a raceme and a 
spike is, that in the latter the flowers are more 
densely inclosed with very short pedicels or none. 
Panicle (Fig. 92, V) bears flower-branches 
in the place of simple flowers. In this case the ^ 
secondary floral axis, or racliis^ gives rise to 
tertiary ones, as in some of the grasses and the 
oat. If the peduncles in the middle of a dense panicle are 
longer than those at the extremities, a thyrse is produced, as 
the lilac and grape, where the panicle is contracted into a 
Fig. 93. 
somewhat ovate form. 
Spihe (Fig. 93, a) is an assemblage of 
flowers arising from the sides of a common 
stem ; the flowers are sessile, or with very 
short peduncles, as some of the grasses and 
mullein. A spike is generally erect. The 
lowest flowers usually blossom and fade be- 
fore the upper ones expand, or the expansion 
is from base to apex. When the flowers in 
a spike are crowded very close, an ear is 
formed, as in Indian corn. 
Umhel (Fig. 93, V) consists of several flow- 
er-stalks, of nearly equal length, spreading out from a common 
center, like the rays of an umbrella, bearing flowers on their 
summits, as in the carrot. If the secondary axes or rays arise 
from the primary ones in the same manner, a comjpound umbel 
is formed, as in the parsnip. A compound umbel bears the 
same relation to a panicle that a simple umbel does to a raceme. 
Cyme (Fig. 93, c) resembles an umbel in having its common 
stalks all spring from one center, but difiers from it in having 
tliose stalks irregularly subdivided ; as the snowball and elder. 
Tlie order of development of these flowers is centrifugal. A 
cyme reduced to a few flowers, is called a verticillaster / crowd- 
Eaceme — Panicle — Spika — Umbel — Cymo. 
