JOHN NELSON: Eastern salt marshes home to charming floral beauties

This week’s Mystery Plant is a bushy one that likes to grow in marshes.

Walking around in a salt marsh can be a challenging experience. You have to select the right trousers and footwear, of course, and depending on the season, you must consider gnats, flies and other visitors. Without a strong breeze and in hot weather, the aroma of the marsh may become stifling.

Then there are the issues of protection from the sun and dealing with treacherous substrates. Pluff mud and oyster shells can be encountered. And, of course, you have to pay attention to the tides.

Despite the care that must be taken in such an outing, the study of natural history in salt marshes is fascinating: a great place to learn about plants and animals of estuarine habitats.

From a botanical view, salt marshes are commonly described as monotonous, often dominated by one or two species. Cordgrass and needle-rush are the common components of many Southeastern salt marshes, covering thousands of acres at a time. Nevertheless, there are some charming floral beauties out there to be enjoyed. Sea-pink, salt goldenrods, marsh asters and fleabane provide plenty of color, along with the tall seaside mallow, so attractive to butterflies.

Here's another one you may have seen but didn't pay much attention to.

It's a bushy plant (the epithet of its scientific name means "shrubby"), spreading from rhizomes and forming colonies. Its leaves are paired on the somewhat woody stem, and the foliage tends to be somewhat succulent and rather grayish. Each leaf is narrowed at the base, occasionally toothy or a bit spiny and with one or a few central veins.

These plants like to grow in marshes, especially on higher ground, and you also can find populations in salt flats or behind dunes, or even in parking lots and open, disturbed areas near the beach.

It is an attractive member of the sunflower family, and thus has its small flowers congested into heads. Bright yellow ray flowers (around the periphery) and disk flowers (in the center) make up a head, which appears from spring throughout the summer. Each of the flowers forms a tiny, angled achene, much like a sunflower "seed." Each of the tiny, central disk flowers is associated with a tough little bract, pointy and sharp at its tip.

Now, at the end of the summer, the corollas wither, but the heads remain intact for a long time and are a common sight in marshes even in the winter. The heads, due to the many sharp bracts within, are rather prickly. "Stickery" would be a good word.

This species is fairly common all along the coast from Virginia to Texas. It extends well into Mexico, and introduced populations are present in the Caribbean. It is adaptable in landscaping, and makes a colorful, shrubby addition to a beach garden.

This week's Mystery Plant is "Sea ox-eye," Borrichia frutescens.

John Nelson is the curator of the Herbarium at the University of South Carolina in the department of biological sciences. As a public service, the Herbarium offers free plant identifications. Visit www.herbarium.org or call 803-777-8196.