singleawned

Singleawned is a term used in plant morphology, primarily in the description of grasses (Poaceae), to denote a spikelet that bears a single awn. An awn is a slender bristle that typically extends from the lemma of a grass floret, though it can sometimes arise from other parts of the spikelet. The singleawned designation contrasts with awnless forms, which lack an awn, and with multi-awned forms, which carry two or more awns on a spikelet.

In taxonomic keys and floras, singleawned is a descriptive character used to differentiate species or varieties. The presence and structure of the single awn—its length, curvature, and whether it is straight or geniculate (kinked)—can aid identification. Awn development and expression may vary with growth stage, environmental conditions, or genetic factors, so observers may note singleawned forms as characteristic in specific contexts or populations.

Functionally, awns often contribute to seed dispersal or placement, sometimes through hygroscopic movement that responds to humidity, which can assist in burial or orientation of the seed. In singleawned grasses, this functional aspect is tied to the behavior of the sole awn.

Overall, singleawned is a descriptive, non-taxonomic character used to document and compare grass morphology, particularly in regional floras and systematic treatment where awn number helps distinguish closely related taxa. See also: awn, spikelet, grass morphology.