Plants annual. Culms 2–35 cm. Sheaths of the flag leaves in-flated; auricles not developed; ligules 1.5–3 mm, rounded to acute; blades 1–5(7) cm long, 1.5–5 mm wide, flat or folded. Panicles 0.5–5.5 cm long, 3–7 mm wide, ovoid to shortly cylindrical, cuneate at the base, widest at or above midlength. Glumes 2.2–4.4 mm, oblong-lanceolate, keels ciliate, tapered, apices parallel or divergent, awns 0.3–1 mm, usually parallel, sometimes divergent; lemmas about 1/3 as long as the glumes, glabrous or pubescent; anthers 0.3–1.2 mm. 2n = 14.
Phleum arenarium is native to maritime sands and shingles of southern and western Europe. In the Floraregion, it is known only from old ballast dump records.