Principles of Classification. 
IB 
mosa produces an aggregate raceme, where several are 
collected together. 
The spike, spica , is characterised by numerous flow- 
ers on a common stalk, without partial stalks, as in 
broad-leaved plantain. Sometimes the spike is com- 
pound, as in lavandula pinnata ; and when the flowers 
are all on one side, it is called spica secunda. A spi- 
cula, or spikelet, is applied to the grasses which have 
many florets in one calyx, as in poa aquatica. 
Corymbus, or corymb, is a spike with partial flower- 
stalks, gradually longer as they are lower on the com- 
mon stalk, so that all the flowers are nearly on a level, 
as in the common cabbage, which becomes a raceme 
when it is in fruit. 
Fasciculus^ or fascicle, is applied to flowers which 
have little stalks variously inserted and subdivided, but 
collected into a close bundle, which is level at the top, 
of which common sweetwilliam is a good example. 
Capitulum, a head or tuft, has sessile flowers ar- 
ranged in a globular form, as in sea-pink and globe- 
amaranthus. 
XJmbella, or umbel, has several flower-stalks or rays, 
nearly of equal length, rising from a common centre, 
and the summits forming a level, convex, rounded, and 
rarely a concave surface. It is called a simple umbel 
when each ray has a single flower, and compound when 
each stalk or ray supports a small or partial umbel. 
This peculiar distribution of the flowers is the origin of 
the name of a natural order of plants, which are thus 
denominated mnbellated, or umbelliferous^ as the com- 
mon carrot, parsley, and hemlock. 
Cyma, or cyrne^ agreeing in general appearance with 
the umbel, has the stalks arising from one centre, but 
