Sphenopus

Shenopus* Fund. Agrostogr. 135 (1822).

Derivation:. From the Greek sphen (wedge) and pous (foot), in reference to the distally thickened pedicels.

Key references (keys and floras):. J.P.Jessop, Flora of South Australia 4:1903 (1986); B.K.Simon, Key to Australian Grasses 159 (1993); D.Sharp and B.K.Simon, AusGrass (2002); J.P.Jessop, Grasses of South Australia 168 (2006); A.Wilson (ed.), Flora of Australia 44A: Poaceae 2: 339 (2009).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (140).

Naturalised. 2 species, from Mediterranean to western Asia. 1 species in Australia, SA.

Habit. Annual, tufted. Leaf blades narrow. Ligule an unfringed membrane.

Inflorescence. Inflorescence paniculate (with numerous, very small spikelets).

Spikelets. Spikelets laterally compressed, long pedicelled (the pedicels claviform); with naked rachilla extension. Fertile spikelets elliptic, laterally compressed, disarticulating above glumes.

Glumes. Glumes minute to relatively large, unequal, shorter than spikelet, shorter than adjacent lemmas, rounded or truncate, awnless, keeled, dissimilar to similar (hyaline to membranous, rounded to emarginate, the lower smaller). Lower glume 0 nerved or 1 nerved. Upper glume 1 nerved.

Florets. Fertile florets 2–7. Lemmas similar in texture to glumes (membranous, with hyaline margins wider above), entire at apex, pointed or blunt, muticous, 3 nerved, with nerves non-confluent, 3 keeled. Palea relatively long, tightly clasped by lemma, entire or apically notched, thinner than lemma to textured like lemma (hyaline), 2 nerved, 2 keeled. Palea keels wingless. Callus short, blunt (glabrous). Lodicules 2. Stamens 3. Stigmas 2. Grain small (1–1.2 mm long in S. divaricatus), oblong or ellipsoid, compressed laterally or terete. Hilum short. Endosperm liquid, or hard.

Kranz Anatomy. C3.

2n = 12 and 24, 2 and 4 ploid, commonly adventive.

Habitat. Saline soils and maritime sand. Species of open habitats.

Classification. Pooideae; Poeae.

Types Species. S. gouani Trin., nom. illeg..

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