Raceme
A
raceme is an unbranched, indeterminate type of inflorescence bearing
pedicellate flowers — flowers having short floral stalks called pedicels — along its axis. In botany,
axis means a shoot, in this case one bearing the flowers. In indeterminate inforescences like racemes, the oldest flowers are borne towards the base and new flowers are produced as the shoot grows, with no predetermined growth limit. A plant that flowers on a showy raceme may have this reflected in its scientific name, e.g.
Cimicifuga racemosa. A compound raceme, also called a panicle, has a branching main axis. Examples of racemes occur on mustard and radish plants. A
spike is an unbranched, indeterminate inflorescence, similar to a raceme, but bearing sessile flowers. Examples occur on Malabar nut and chaff flowers A
spikelet can refer to a small
spike, although it is primarily used to refer to the ultimate flower cluster unit in grasses and sedges, in which case the stalk supporting the cluster becomes the
pedicel.