Fig 24. [Green Foxtail. Green Pigeon Grass. Setaria viridis] (L.) Beauv. Chaetochloa viridis (L.) Nash.

Green Foxtail. Green Pigeon Grass. Setaria viridis (L.) Beauv. Chaetochloa viridis (L.) Nash. Spikelets, light to dark brown mottled, 2–2.3 mm. long, after threshing or much rubbing consisting of the grain and two firm coverings, the rounded one known as a floral glume which covers the edges of the flattened side, oval, the surface granular and very faintly striate, lengthwise and ridged crosswise. Much resembling Hungarian grass. Introduced from Europe. Found with yellow foxtail.

Fig 25. [Porcupine Grass. Stipa spartea] Trin.

Porcupine Grass. Stipa spartea Trin. Grain inclosed in the floral glume, light brown, 18 mm. long, clothed on the lower half with short brown hairs slanting upward, bearing at the base a sharp, hard, curved beak, when dry the attached awn is twisted for 6 cm. and straight and bent at right angles about 6 cm. When moistened, the awn untwists more or less; twisting and untwisting the beards hold what the beak pierces, thus making it a formidable weapon to enter the skins of sheep, goats and dogs. Fortunately it is seldom abundant. Sandy land Michigan and westward.