spike

noun

(L. spica: spike, ear of corn) A usually unbranched, elongated, simple, indeterminate type of racemose inflorescence in which stalkless (sessile) or subsessile flowers or spikelets, arise from an undivided floral axis, and mature from the bottom upwards, as in plantain and Orchis. In the family Gramineae (Poaceae, sedges and grasses) the flowers are grouped in clusters called spikelets, which may be arranged to form a compound spike (as in wheat). Cf. raceme.