A '''spike[[Spike (botany)]]''' is an unbranched, indeterminate inflorescence, similar to a raceme, but bearing sessile flowers (sessile flowers are attached directly, without stalks).<ref name="Wofford1989"/> Examples occur on Malabar nut (''[[Justicia adhatoda]]'') and chaff flowers (genus ''[[Achyranthes]]'').<ref name="KumarBhatia"/> A '''[[spikelet]]''' can refer to a small spike, although it primarily refers to the ultimate flower cluster unit in grasses ([[Poaceae|family Poaceae]]) and sedges (family [[Cyperaceae]]),<ref name="Wofford1989">{{cite book|last=Wofford|first=B. Eugene |title=Guide to the Vascular Plants of the Blue Ridge|url=https://books.google.com/books?id=mNeNUQkIrqQC&pg=PA12|year=1989|publisher=University of Georgia Press|isbn=978-0-8203-2455-5|pages=10–15}}</ref> in which case the stalk supporting the cluster becomes the pedicel. A true spikelet comprises one or more florets enclosed by two [[glume]]s (sterile [[bract]]s), with flowers and glumes arranged in two opposite rows along the spikelet. Examples occur on rice (species ''[[Oryza sativa]]'') and wheat (genus ''[[wheat|Triticum]]''), both grasses.<ref name="KumarBhatia"/>
