Seed Study - Nassella viridula
Species: Nassella viridula (Stipa viridula)
Vegetative identification: There is a tuft of hair at each edge of the collar plus hairs extending down the outer margin of the sheath. Blades are bright almost lime green, with a prominent mid-rib on the back of the blade and prominent veins on top of the leaves. The leaves are very rough on the upper surface and to a lesser extent on the bottom. Blades are rolled at emergence and seedlings often have a twist at the end of the blade.
Nassella viridula – green needlegrass
Average number of good seeds per gram bulk matter: n.m.
Average number of good seeds per gram cleaned: 226
Commercial estimates of seeds per gram: 370, 365
Percent seed: 85
Percent live: 95
Collection dates: July 7 and 9
Collection effort: 216 grams per 14 person hours
Collection notes: Seed is dispersed soon after it matures, so watch closely when it begins to ripen. The seeds on each rachis mature at different times. It works well to pull a closed hand (instead of using a fingernail) gently along the rachis to dislodge only mature (dark colored) seed and leave immature seed (green or light colored) behind.
Cleaning notes: Clean seed measurement was with awns attached and a few stalks but was mostly pure seed.
Did You Know?
Winds caused by changes in barometric pressure are what give Wind Cave its name. These winds have been measured at the cave's walk-in entrance at over 70 mph. The winds at the natural entrance of the cave attracted the attention of Native Americans and early settlers.