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GRASSES OF THE COLUMBIA BASIN OF BRITISH COLUMBIA Heather Stewart, Richard Hebda Major Groups of Grasses Table of Contents Glossary Torreyochloa A number of species formerly contained in Glyceria have been moved into Torreychloa and Puccinellia. All three genera have awnless lemmas and lemma nerves that are parallel rather than meeting at the tip. The five lemma nerves of Puccinellia are less obvious. The five to seven nerves of Torreychloa and Glyceria are raised in both species. Torreychloa has open to partially open leaf sheaths in contrast to Glyceria, which has closed leaf sheaths. Torreychloa was named after J. Torrey, an early American botanist. The two species of Torreychloa in British Columbia are Torreychloa pallida and Torreychloa pauciflora.   Torreyochloa pauciflora (J.S. Presl) Church Weak Alkaligrass Weak False-manna Plant: Torreyochloa pauciflora is a native species that grows to 30-150 cm tall. It is a perennial that is often bent at the base, with well-developed rhizomes and a broad, open flowerhead. Leaves and Stem: The lower part of the stem may rest on or near the surface and root at the nodes. Sheaths are open to partly closed. The leaf blades are flat, 3-15 mm wide and feel slightly rough to the touch. There are no auricles. The ligule is 3-9 mm long and has a pointed, tattered tip. Flowerhead and Flowers: The flowerhead is 5-20 cm long, open and rather loose. The two to three branches per node are perpendicular to the stem axis or even drooping. Spikelets are three- to seven-flowered. Two, small, unequal glumes are much shorter than the first flower. Lemmas are 2-3 mm long, have rounded margins and a purple band just below the edge of the margin. Habitat: Weak Alkaligrass grows in the shallow water of marshes, swamps and wet meadows in sites such as Sage Creek in the Flathead, Nelson and near Cranbrook. Similar Species: You can tell this species from other Alkaligrasses (Puccinellia spp.) by its long prominent ligule and wide leaf blades. Technically, it has more prominent nerves on the lemma. Weak Alkaligrass is also known as Puccinellia pauciflora (Presl) Munz, and Glyceria pauciflora J.S. Presl in C.B. Presl.

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