Weed of the Month: Echinochloa crus-galli (barnyard grass)

Echinochloa crus-galli (barnyard grass) spikelets with purple stigma

Echinochloa crus-galli is commonly known as cockspur (or cockspur grass), barnyard millet, Japanese millet, water grass, common barnyard grass, or simply "barnyard grass".

Echinochloa crus-galli (barnyard grass) with yellowish anthers

This species is considered one of the world's worst weeds, because it reduces crop yields and causes forage crops to fail by removing up to 80% of the available soil nitrogen.

Echinochloa crus-galli (barnyard grass), no ligules

It is an invasive weed in all the states in the continental USA, and is particularly adapted to wet areas such as paddy fields

I found it growing from the side of a stand of Imperata cylindrica (Japanese Blood Grass).

Specimen of this cosmopolitan grass from the Philippines

I identified it from the absent ligule and the distinctive inflorescence, including the fact all the spikelets were crowded on only one side of the central axis.

Echinochloa crus-galli (barnyard grass), with purplish base