spikelet: a unit of the inflorescence, usually consisting of two glumes and one or more florets (each with palea and lemma between which the flower is borne).

callus: the hard, usually pointed base of the spikelet (as in Heteropogon, Andropogon, and related genera) or of the floret (as in Aristida and Austrostipa), just above the point of disarticulation. In the former case, the callus is a portion of the rachis; in the latter, it is a portion of the rhachilla. In Eriochloa the callus is the thickened node and remnant first glume; in Chrysopogon it is part of the pedicel. adj. callose.

oblong: having the length greater than the width but not many times greater, and the sides parallel.