Panicum capillare

Witchgrass

View of Panicum capillare, common name Witchgrass.

Witchgrass shows small oval spikelets on flimsy branches, much like a huge Annual Muhly.

Leaves of Panicum capillare are large compared to the wispy stems and branches.

A field view of Witchgrass. The panicle or seedhead can be over a foot long and wide.

The inflorescence of Panicum capillare is dainty. The panicle takes up about half of the whole plant.

Witchgrass roots.

The spikelets are often very separated, but check the photos above--it varies.

In this closer view you can see the tiny black lower glume on the bottom spikelet.

Here are three spikelets up close.

How to Identify Witchgrass

Witchgrass is an annual bunchgrass. It is one of the wispiest of grasses, with widespread "seeds"(spikelets) isolated on thin branches. In a sense, there are three sizes of such grasses, each a different species. You can distinguish them simply by size. Switchgrass is the largest, often planted as an ornamental. Witchgrass is medium sized, averaging a couple feet tall. Annual Muhly is tiny, often under six inches tall and covering the ground like a semi-visible mist.

Similar Species

"Dots on Threads" is my name for several wide-panicled grasses that have separated seeds on separate thin branches. In addition to the three above, dots on threads include several "tiny Muhly's," that are very similar, plus Agrostis scabra, Digitaria pubiflora, and Sporobolus texanus (this last only in COCO). Eventually I will have all of these on this site; meanwhile just see them as dots on threads (most are uncommon). Remember that this summary exists here. It includes all of Arizona's dots on threads.

When you identify the dots on threads, you must first eliminate many Lovegrasses (Eragrostis species). Some of these look like dots on threads, but their "dots" (spikelets) are quite elongate and each dot has many florets per spikelet instead of one oval "seed." It is useful to remember the general look of Lovegrasses. They look like tiny spear points. They are diverse and abundant (16 species) in Arizona, but it is quite difficult to differentiate among them. Most Arizona naturalists may prefer to call all of these "Lovegrasses" or "Eragrostis species." Here are three photos of general Lovegrass aspects: