Ctenium aromaticum aka Toothache Grass

Ctenium aromaticum, or toothache grass, belongs to the grass family, Poaceae. This perennial grows during the warm season and forms upright clumps. Its native range runs from New Jersey into the southeastern United States. It grows in wet savannas and flatwoods on the Coastal Plain. The whole plant has a scent, including its green, round stems.

Plants grow 1–5 feet [0.3–1.52 metres] tall. Clumps spread 1–3 feet [0.3–0.91 metres] wide and grow fast. The long, narrow leaves have smooth edges and alternate along stems. Their upper faces look blue-green, while their undersides are pale green. Leaves near the ground grow longer than those on stems. Old leaf sheaths leave a fibrous layer around each clump’s base. The foliage gives the plant a fine texture.

Green, scented flowers appear from mid- to late summer. After a burn, flowering may extend into early autumn. Fire also promotes more flowers and seeds. Each flower head sits at a slight angle to its stem. Awned spikelets line one side of the central stalk. This gives the head the look of a narrow comb. Each spikelet’s second glume bears two clear rows of glands. The brown fruit is an awned grain, called a caryopsis. Once seeds fall in autumn, the heads twist into spirals. These seed heads add interest through autumn and winter.

Grow toothache grass in sun; it also accepts partial shade. It prefers moist, acid soil, including clay and loam. It also grows on sandy sites. Plants cope with flooding and brief dry spells, but not salt. North Carolina State lists USDA hardiness zones 8a through 10a. It rates upkeep as low and notes resistance to deer and heat. Seed is the listed means of propagation. Plants can be hard to find for garden use.

This grass suits rain gardens, meadows, containers, and native plantings. Use it in small groups or larger masses on wet sites. It attracts butterflies and hosts skippers. Birds eat its seeds. Birds, reptiles, and small mammals also find cover among the clumps. Grazing mammals may eat the leaves but favor other plants. Roots and lower stems contain isobutylamides that numb the mouth when chewed. Past uses include raising saliva flow and a possible toothache remedy. These uses do not establish that the plant is safe to eat.