The cricket’s chirp, the shorter days, the bloom of goldenrod and cotton-grass – all are bittersweet signs of the passing of the seasons at Acadia National Park.

The white tufts of cotton-grass particularly sadden Jill E. Weber, co-author of the field guide, “The Plants of Acadia National Park,” because “it means summer’s almost over.”

Though you may never have seen cotton-grass, you will know it when you see it.

A hiker points out a field of cotton-grass in the distance in Acadia National Park.

Four varieties of cotton-grass are listed in “The Plants of Acadia National Park,” a project of the Garden Club of Mount Desert, Friends of Acadia and the Maine Natural History Observatory, and they all have a distinctive cottony bloom and grow in wetlands.

Despite its name and appearance, cotton-grass is not a grass, but a sedge. In fact, about a quarter of the plants in Acadia are grass-like, some of which are sedges, others of which are rushes, and the rest true grasses. Acadia’s web site even features a handy rhyme to distinguish a sedge from a rush from a grass.

Cotton-grass is only found on occasion on Mount Desert Island, Schoodic Peninsula and Isle au Haut – that is, in a sporadic and scattered fashion – according to “The Plants of Acadia National Park,” a 530-page guide which features color photos and descriptions for 862 plants. Contrast that with common plants, such as certain varieties of goldenrod, which can be widespread and occurring in large numbers.

To help you identify typical habitats for various plants, whether cotton-grass or goldenrod or any of the hundreds of other species found in Acadia, the park’s Web site has a handy checklist.

The first time we ever saw cotton-grass was on Isle au Haut, along the Long Pond Trail. The perennial can also be found at Wild Gardens of Acadia, or on summits with boggy spots, like Sargent Mountain, according to Weber.

Cotton-grass on the Long Pond Trail on Isle au Haut.

Though we’ve seen cotton-grass in bloom in Acadia a few times since our hike on Isle au Haut, it was not until this month that we learned from Weber that it signals the end of summer, as we’ve always known goldenrod to mean.

Whether it’s cotton-grass or goldenrod that is a mournful reminder of summer’s end, perhaps the promise of Acadia’s glorious fall foliage can ease the pain, at least for a while.

Or perhaps the verse of Robert Frost, who made poetry out of the passage of time and season, can take away some of the sting. Frost isn’t talking about Bar Harbor in this 1923 work, but the town used to be known as Eden, before a name change in 1918:

Nothing Gold Can Stay
by Robert Frost

Nature’s first green is gold,
Her hardest hue to hold.
Her early leaf’s a flower;
But only so an hour.
Then leaf subsides to leaf.
So Eden sank to grief,
So dawn goes down to day.
Nothing gold can stay.

What marks the end of summer in Acadia for you?