With wildflowers distracting the eye with bursts of bright color, it’s often easy to overlook some of the island’s most common plants, grasses, many of which are blooming right now. While most grass species lack brilliant colors and have small flowers, they are an important part of the ecosystem, feeding many familiar herbivores, from voles to rabbits and deer. And some are also vital host plants for different types of insects.

Pausing to take a look at grasses as you walk through our conservation properties can really clue you in to a whole new botanical world. On recent walks and field trips I’ve found some truly beautiful grasses that called out for attention. Their graceful flowers and fine foliage capture the early summer light and create quite a spectacle, especially late in the day with the last rays of sunlight shining through. In many cases, the roots of grasses run much deeper than you expect, and from dunes to wetland edges and the moors, grass root systems anchor entire plant communities.

Poverty oatgrasses (Danthonia spicata) silhouetted against a backdrop of shrubs and sky, Middle Moors. Photo: K.A. Omand

Poverty oatgrasses (Danthonia spicata) and woodland oatgrasses (Danthonia compressa) are nearing their peak and beginning to set seed in the latter half of June. The name “poverty oats grass” seems a less apt choice for these grasses when they are in full bloom and covering recently disturbed areas like the Caterpillar trail in the Middle Moors, which winds over the Shawkemo Hills along a recently brush-cut firebreak. In this area I identified several areas with woodland oat grasses, which are often overlooked because they appear so similar. As the name implies, they like woodlands and openings; another common name is trail oatgrass, which may be even more fitting, as at least on Nantucket they seem to thrive along trails in shrubland. These small grasses will soon fade from view as they go to seed, leaving poverty oatgrass distinguished only by the curly wigs of last year’s dried basal leaves which remain entwined with this year’s green leaves.

Woodland or trail oatgrass (Danthonia compressa) lacks the curly dried mops of last year’s basal leaves. Photo: K.A. Omand

The woodland oatgrass may be even more obscure as it lacks the curly basal leaves, once the flowers drop. Right now and into seed set, however, they are putting on a good show. The flowers are encased in long glumes, and the awns of the lemmas are easy to see and catch the light. Poverty oatgrass is found in many habitats around the island, occupying dry sandy areas that many other plants cannot tolerate and taking the punishment of many feet along trails.

Leonard’s skipper butterfly (Hesperia leonardus) sipping from a pasture thistle (Cirsium pumilum). Photo: C. Beaton.

We often forget that the larvae of many species of insects require certain plant species to develop, and tiny poverty oats grass clumps feed the caterpillars of native skipper butterflies, including the Leonard’s skipper (Hesperia leonardus), pictured above as an adult butterfly feeding on the nectar of another native plant, pasture thistle (Cirsium pumilum). Learn more about skippers and other Massachusetts butterflies.

Clouds of pink and silver wavy hairgrass (Deschampsia flexuosa) flowers backlit by the evening sun on the Caterpillar firebreak. Photo: K.A. Omand.

Another grass species that is showing off this time of year in the Middle Moors, wavy hairgrass (Deschampsia flexuosa), has clouds of tiny silvery flowers on pink to red stems, making it stand out when the sun is low in the sky and the plants seem spotlighted. Wavy hairgrass makes appearances in other parts of the island, but really is most abundant in the Middle Moors and on Coatue, where it grows in large densities. Native cool season grasses like poverty oat grass and wavy hairgrass thrive in spring, flower by the end of June, then cede the stage to warm season grasses such as little bluestem and switchgrass.

A large wavy hairgrass in full flower in the Serengeti near Milestone #5. Photo: K.A. Omand.

A much rarer early season find is black seeded spear grass (Piptochaetium avenaceum). This species is never a very common sight across the island but seems to be having an unusually good blooming year in 2021 popping up in a few locations from the Middle Moors to Tom Nevers and Smooth Hummocks. This grass has long needle like awns that can be straight in flower (like spears as in the common name) but twist and contort when drying.

Black seeded spear grass (Piptochaetium avenaceum) in bloom in the Middle Moors along a road edge, with its awns (long needle-like spears) straight. Photo: K.A. Omand.

The flowers themselves look like dark grains of rice on long stalks, with the spearlike awns protruding from the tips. The flowers darken to black as the seeds mature inside. Small patches of this grass may greet you as you walk along road edges, particularly in the Middle Moors, where it seems to flourish and then disappear from year to year, to pop up somewhere else.

Close-up of black seeded spear grass flowers and awns. Photo: K.A. Omand.

At the beginning of July, the warm season grasses will pick up their growth rate, so be sure to keep an eye out as the season progresses to notice more of these interesting and vital plants. Nantucket’s open landscapes offer many areas with abundant grasslands and heathlands, habitats that are declining with succession and development off island.