Publication: Sp. Pl. 1: 68. 1753.
selected vouchers: WTU
Notes: FNA24: "Poa annua is one of the world's most widespread weeds. It thrives in anthropomorphic habitats outside of the arctic. A native of Eurasia, it is now well established throughout most of the Flora region.
Poa annua is a gynomonoecious tetraploid (possibly rarely polyhaploid), and is thought to have arisen from hybridization between P. infirma and P. supina (Tutin 1952). It is similar to P. infirma, differing in having larger anthers. It differs from P. chapmaniana in having glabrous calluses and three larger anthers, rather than one. Forms with glabrous lemmas occur sporadically within populations."