He tossed them over the porch rail and into an ancient flowerbed where only witchgrass and dogweed grew.    From Wordnik.com.  [The Waste Lands]

K'shar pushed aside the tangled witchgrass and gazed upon the half-metamorphosed milestone with curious golden eyes.    From Wordnik.com.  [Curse of the Shadowmage]

They found Kellen kneeling by the side of the dirt road, peering at something amid a tangle of brambles and witchgrass.    From Wordnik.com.  [Curse of the Shadowmage]

He hurriedly made his way through the garden This late in the year, the garden was mostly a tangle of dried brown plants and witchgrass.    From Wordnik.com.  [Curse of the Shadowmage]

We must accept whatever good can be got out of it, and keep it under as we do sorrel and mullein and witchgrass, by enriching the soil, and sowing good seed in plenty; by good teaching and good books, rather than by wasting our time in talking against it.    From Wordnik.com.  [Medical Essays, 1842-1882] Reference

Further up there was witchgrass, sparse, then green and rank" then the first sweet smell of real grass, mixed with timothy and shaded by the first of the dwarfed firs.    From Wordnik.com.  [The Gunslinger]