• Wind Cave National Park - Two Worlds

    Wind Cave

    National Park South Dakota

Seed Study - Nassella viridula

Nassella viridula (Stipa viridula) - Green Needlegrass

Nassella viridula (Stipa viridula) - Green Needlegrass

NPS Graphic

Species: Nassella viridula (Stipa viridula)
Common name: green needlegrass

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.

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