Looking like less-colorful miniature versions of Dr. Seuss’ truffula trees, tawny cotton grass (Eriophorum virginicum) is an obligate wetland plant found in bogs, fens and wet meadows throughout New England. The fluffy “cotton” puff-ball tops of this plant are actually the modified sepals and petals of minute flowers. The tawny-colored silky hairs that give cotton grass its distinctive look continue to elongate as the seeds mature, aiding in wind dispersal of the seeds (similar to the parachute-like seeds of a dandelion). When present in great numbers, they can be particularly showy. In the bog where I found the cotton grass pictured here, from a distance the cotton grass plants gave the impression of  little dollops of snow across the bog’s surface.

The “tawny” name refers to the fact that the cottony tufts of this species have a tannish to yellowish hue, whereas other cotton grass species are pure white. The genus name Eriophorum is derived from the Greek words “erion” for wool or cotton and “phoros” for bearing (i.e., a “cotton-bearing” plant). Although plants in this genus are often referred to as cotton “grass”, they are not true grasses. Instead, they are grass-like plants belonging to the sedge family (Cyperaceae). Although the stem of tawny cotton grass is round towards its base, it is triangular towards the top. If in doubt, the helpful the mnemonic “sedges have edges, rushes are round, grasses have nodes from their tips to the ground” can help you sort out cotton grass and other grass-like species into their appropriate groups. Do you have any fun or useful nature mnemonics?