One morning earlier this month, I spent a few hours kayaking in a shallow pond that was home to a vast colony of blooming Pickerelweed (Pontederia cordata). I've known, or at least recognized, Pickerelweed, for over a decade now as a common aquatic plant with arrow-shaped leaves and a blue-purple flower spike, but I'd never looked at the plant's flowers up close -- they are so hairy.
According to John Eastman (The Book of Swamp and Bog, 1994, p. 143), dragonfly and damselfly nymphs commonly climb up Pickerelweed plants when they're ready to transform into winged adults and leave their empty exoskeletons behind as evidence.
Eastman also notes that various dabbling ducks, such as American Black Duck, Mallard, and Northern Pintail, eat the seeds of Pickerelweed, which ripen in late summer. Though I've not yet tried them, humans can also eat the seeds raw, roasted, or boiled. For more details on human uses, see Ancestral Plants (Vol. 1, 2010, p. 166) by Arthur Haines.
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