Plants annual or perennial; cespitose. Culms 13-100(250) cm, not woody. Sheaths open; ligules of hairs or membranous and ciliate; blades flat or loosely involute. Inflorescences terminal, panicles of numerous spikelike branches on elongate rachises. Spikelets in 2 rows on 1 side of the flat or trigonous branch axes, with 2-8 florets, additional reduced florets sometimes present distal to the functional florets; rachilla internodes tipped with a few short hairs; disarticulation initially above the glumes and between the florets or the lemmas falling and the paleas persistent, subsequently at the bases of the panicle branches. Glumes unequal, shorter than the spikelets, keeled, acute to acuminate, unawned; lemmas 3-veined, keeled, membranous, acute, acuminate, or shortly awned; paleas shorter than the lemmas. Caryopses ellipsoid to fusiform. x = 10. Name from the Greek pogon, beard, and arthria, joint, an allusion to the hairs on the rachilla joints.

Pogonarthria includes four species, all of which are native to tropical and southern Africa. One species has become established in Arizona.

Ingram and Doyle (2004), based on nuclear and plastid sequence data, concluded that Eragrostis is monophyletic if four segregate genera are included: Acamptocladus, Diandrochloa, Neeragrostis, and Pogonarthria. We are not, at this stage, prepared to emend the treatments of Pogonarthria and Eragrostis to reflect their findings. [Note added by Barkworth, 2004].

1.   Pogonarthria squarrosa (Licht.) Pilg.
Herringbone Grass, Sekelgras

Plants perennial; densely cespitose. Culms 27-100(140) cm, stiffly erect, unbranched, glabrous. Sheaths mostly shorter than the internodes, glabrous; ligules 0.5-1 mm, of hairs; blades 4-30 cm long, 2-5.5 mm wide, adaxial surfaces smooth to slightly scabrous. Panicles 20-30 cm, with 50+ branches; rachises more or less scabrous; branches 2-3 cm, arcuate, axes more or less scabrous. Spikelets usually with 4-8 florets. Lower glumes 0.8-1.5 mm, 1-veined; upper glumes about 2.5 mm, 1-3-veined; lemmas about 3 mm, glabrous, mostly smooth, keels scabridulous; paleas about 2 mm, keels scabrous; anthers about 1 mm. Caryopses 1.2-1.3 mm, fusiform, light brown; embryos less than 1/2 as long as the caryopses. 2n = 120.

Pogonarthria squarrosa is native to eastern and southern Africa, where it is said to be common. In the Flora region, P. squarrosa grows spontaneously only in a small area in the foothills of the Huachuca Mountains, Cochise County, Arizona, at an elevation of about 1450 m, where it seems to be competing well with native grasses and Eragrostis lehmanniana, another African introduction. The plants tend to grow in rather dense colonies of a few square meters, scattered through the area. It is a handsome species that turns reddish-brown as it matures, causing it to stand out among its associates.