Aira caryophyllea L. - Silver Hairgrass

Aira caryophyllea plant

Family - Poaceae

Stems - To +/-20cm tall, erect, multiple from base, glabrous, from fibrous roots.

Leaves - Small, thin, to +/-4cm long, +/-1mm broad, scabrous. Sheaths scabrous. Ligule scarious, to +/-3mm long, typically erose on the margins.

Inflorescence - Open, branched panicle making up 1/3 to 1/2 of the plant height. Panicle branches ascending, glabrous. Stalks of the individual spikelets to 5mm long, glabrous.

Aira caryophyllea inflorescence

Flowers - Spikelets mostly scabrous, to 3mm long. Both the lemmas of the spikelet with an awn to +3mm long.

Aira caryophyllea spikeletArrows show awns of lemmas.

Flowering - May - June.

Habitat - Lawns, pastures, fields, disturbed sites, igneous glades, roadsides.

Origin - Native to Eurasia and Africa. Introduced nearly worldwide.

Other info. - This diminutive grass can be found in the southern part of Missouri. The plant was first reported in the state in 1982. A. caryophyllea is easy to ID in the field because of its small size and the fact that both of the lemmas of the florets are awned. Another species, A. elegans is similar, but is slightly larger and has florets with only one awned lemma. This latter species is slightly less common in the state.

Photographs taken somewhere in North Carolina, 4-26-03.


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