In honor of Halloween:
Witchgrass (Dichanthelium acuminatum) is a perennial bunchgrass (grows in tufts or clumps) that is found in moist sandy ground along lakeshores, streams and beaches, and rocky or gravelly areas in bogs, meadows or open forests. These particular species were growing in the rocks surrounding Eagle Lake (Lassen County CA).
A native grass, witchgrass can be found throughout North America except in Alaska, and the most northern parts of Canada. The scientific name for witchgrass has changed over time and it is referred to in the literature as Panicum occidentale, Panicum acuminatum and several other older names. Common names include ticklegrass, panic grass, witches hair and tumbleweed grass.
Witchgrass is bushy and branched from the base. The panicle (branched flowering cluster blossoming from the bottom up) is open with long spikelets. The flowering part of witchgrass looks feathery. The purplish flowering heads become brittle at maturity and will break off and tumble in the wind scattering seeds as they blows along.
Witchgrass is a desirable member of natural communities. Before the seeds develop, witchgrass is moderately palatable to livestock as a forage, but is worthless as feed once the seed heads mature. Birds and small mammals do utilize the seeds though. In agricultural and landscaped settings witchgrass can become invasive and weedy and for that reason is often considered a noxious weed.
To me witchgrass is a pretty grass and one that is easily identified in the field.