Awnless Spiralgrass

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem nodes bearded or hairy, Plants conspicuously hairy, grayish, or wooly, Plants viscid, sticky, glandular-hairy, Plants aromatic or malodorous, Stem internodes solid or spongy, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, h ispid or prickly, Leaf sheath hairy at summit, throat, or collar, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence single raceme, fascicle or spike, Inflorescence branches more than 10 to numerous, Rachis angular, Flowers bisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet 3-10 mm wide, Spikelets with 8-40 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glumes 8-15 nerved, Glumes 2-5 toothed, Lemmas thin, chartaceous, hyalin e, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 8-15 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis minutely rugose.

Tuctoria greenei is a species of grass endemic to California. Its common names include awnless spiralgrass and Greene's tuctoria. It is included by the California Native Plant Society on list 1B.1 (rare, threatened, or endangered). It is also listed by the state of California as rare and by the Federal Government as endangered, having been federally listed on March 26, 1997.

This grass typically occurs in vernal pools in open grassland on the eastern side of the Sacramento and San Joaquin Valleys. This endangered species is threatened by the destruction of its already rare vernal pool habitat. Processes causing this habitat destruction include agriculture, urban development, overgrazing and trampling by livestock, alterations in hydrology, and introduced species.