Whorled Pigeon-grass - introduced (*Setaria verticillata)

Native to temperate northern hemisphere. Annual. C4.

Family. Poaceae (Grass family).

Whorled Pigeon-grass is common in disturbed areas.

Identification:

• it is a summer grass - it begins to grow strongly in mid-summer.
• the flower forms a dense, cylindrical cluster, about a centimetre wide
• bristles rise from the flower stalks, just below the spikelets
• the 1st glume is half spikelet length, the 2nd glume as long as the spikelet
• the spikelets have a lower sterile lemma and an upper fertile lemma
• the leaves are flat
• the ligule is a fringed membrane, 1-2mm long.

There are one to four bristles growing from the base of each spikelet. The bristles are longer than the spikelets, and barbed with upward directed teeth.

The summer growth, the bristles from the base with upward-pointing teeth, and the dense cylindrical flower clusters are distinctive.

Setaria: from seta, a bristle. verticillata whorled i.e. arranged in one or more rings around the axis.

---