Periballia* Fund. Agrostogr. 133 (1820).

Derivation:. From the Greek peri (around) and ballo (to throw), allusion obscure.

Syn: Molineriella Rouy.

Key references (keys and floras):. J.P.Jessop, Flora of South Australia 4: 1913 (1986) as Molineriella; B.K.Simon, Key to Australian Grasses 143 (1993); S.W.L.Jacobs and K.L.McClay, Flora of New South Wales 4: 595–596 (1993); N.G.Walsh, Flora of Victoria 2: 459 (1994) as Molineriella; D.Sharp and B.K.Simon, AusGrass (2002); J.P.Jessop, Grasses of South Australia 238 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th ed, 302 as Molineriella (2008); A.Wilson (ed.), Flora of Australia 44A: Poaceae 2: 153 as Molineriella105 (2009).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (190).

Naturalised. 3 species, from Mediterranean. 1 species in Australia, WA, SA, NSW, and Vic.

Habit. Annual, tufted (or the culms solitary). Leaf blades narrow. Ligule an unfringed membrane.

Inflorescence. Inflorescence paniculate.

Spikelets. Spikelets laterally compressed, pedicelled; with rachilla terminating in a floret. Fertile spikelets laterally compressed, disarticulating above glumes, with distinctly elongated rachilla internodes between florets.

Glumes. Glumes more or less equal, shorter than spikelet, shorter than adjacent lemmas, awnless, similar (membranous). Lower glume 1–3 nerved. Upper glume 1–3 nerved.

Florets. Fertile florets 2. Lemmas lanceolate, less firm than glumes (hyaline) or similar in texture to glumes, entire at apex to incised, awned, 3–7 nerved, glabrous, not keeled. Palea tightly clasped by lemma, 2 nerved. Lodicules 2. Stamens 3. Stigmas 2. Grain small, narrowly ellipsoid, longitudinally grooved (or flattened, on one face). Hilum short. Embryo small. Endosperm liquid.

Kranz Anatomy. C3.

2n = 8, 14, and 18, 2 ploid, commonly adventive.

Habitat. Xerophytic. Dry sandy places. Species of open habitats.

Classification. Pooideae; Poeae.

Notes. Somewhat heterogenous, each species having a different chromosome number (Clayton and Renvoize, 1986).

Types Species. P. hispanica Trin.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith