Identifying Grass Weeds

1. Identifying Grass Weeds • Stem/culm • Node • Leaf • Sheath • Collar • Blade • Midrib

2. Vernation • Vernation is a term used to describe how the youngest grass leaves are arranged in the shoot • Folded vernation • Leaves that are folded in the shoot and appear V-shaped in shoots that are cut in half across the width (cross-sectioned) • Rolled vernation • Leaves are circular or “rolled" in the shoot and do not have folds • Determining vernation: • Roll test • Cross-section

3. Ligules and Auricles • Ligules are membranous or hairy tissues located at the junction of the leaf blade and leaf sheath • Ligules can be membranous, a fringe of hairs, or absent • Auricles are slender extensions of the collar and are located at the junction of the leaf blade and leaf sheath • Auricles can be long and clasp around the stem or shoot, small or rudimentary, or absent

4. Growth habit and inflorescence (seed head) Rhizomatous Bunch Stoloniferous Panicle Spike Raceme

5. Green foxtail • Scientific name: Setariaviridis • Family: Poaceae • Life cycle: Annual • Where found: Cropland • Physical description: • Seed: 1-2 mm, pale lemma covering seed • Seedling blade: broad and arched • Leaf blades mostly hairless • Vernation: round • Ligule: hairy • Inflorescence: compact panicle • Fibrous root system • Interesting facts: • Latin name describes inflorescence • Seta=bristle, viridis=green • Also called green bristlegrass

6. Jointed goatgrass • Scientific name: Aegilopscyclindra • Family: Poaceae • Life cycle: Annual • Where found: Cropland • Physical description: • Seed: attaches firmly to lemma and paleaat each joint • Seedling blade: first blade tall, narrow and vertical • Leaf blades with long hairs on margins of blade and collar • Vernation: round • Ligule: membranous with toothed margin • Inflorescence: columnar spikelet with distinctive joints • Fibrous root system • Interesting facts: • May behave as a winter annual in some areas • Known to hybridize with wheat