By Bill McCarron
Special to the Herald-Banner
Wildflowers make for intriguing study because, unlike animals, they don’t run or fly away. Rockwall has a variety of late summer native wildflowers, many of them easy to spot along the cement or dirt walkways that stretch through the city’s parks or close environs.
At the opening of the pedestrian path at Squabble Creek Mountain Bike Trail, one can see abundant patches of Snow-On-The-Prairie (Euphorbia bicolor). As its botanical name implies, Snow’s petallike glands around the rim are streaks of green and white.
Along an edge of The Park at Emerald Bay, one can spot Eryngo (Eryngium leavenworthii). Eryngoes are bright purple and resemble miniature pineapples growing at the end of stems. The botanist responsible for discovering the plant was Melines Conklin Leavenworth (1796-1862), a U.S. Army surgeon and botanist.
Both Snow and Eryngo also blanket Travis Rhodes Trail atop the levee on the west end of Caruth Lake. A smaller late summer lingerer, Dakota Vervain (Glandularia bipinnatifida), with its canopy of purple flowers also rests among the grasses adjacent to the levee trail.
False ragweed (Parthenium hysterophorus) lines many Rockwall pathways. It’s hard to believe that this hay-fever-producing ‘weed’ is actually a member of the Aster Family.
A half-mile-long park sidewalk meanders under the bridge at North Lakeshore Drive, through meadows, and under the bridge at Hwy. 205. Just down from the Lakeshore entryway, one can pick out examples of the bright yellow Saw-Leaf Daisy (Grindelia papposa).
The apex of one of Rockwall’s latest residential developments, The Preserve, is home to three more yellow wildflowers: the soaring Common Sunflower (Helianthus annuus), the more subdued Partridge Pea (Chamaecrista fasciculata), and the ground-hugging Buffalo Bur (Solanum rostratum).
Adjacent to some of Rockwall’s highways and byways, the wildflower enthusiast can come across Silver-Leaf Nightshade (Solanum elaeagnifolium) which displays a cross-shaped lavender flower, each with multiple yellow anthers. When added to a cream base, the berries of this plant reportedly are a cure for poison ivy’s itchy rash.
Nestled in an open Rockwall field is a grove of Bois d’Arcs. True, the Bois d’Arc or Osage-Orange (Maclura pomifera) is a tree and not a flower. However, its late summer display of grapefruit-sized horse-apples (its fruit) makes it conspicuous as a so-called dioecious species (separate male and female trees with separate male and female flowers). The tree’s oily wood never rots; thus, it was a staple for fence posts and house foundations in earlier North Texas times.
Despite its popularity in North Texas lore, the Bois d’Arc leaves much to be discovered about its botanical heritage. To date, for example, genetic studies of the species are non-existent. Although a member of the Mulberry Family, it is the sole member of the Genus Maclura.
Indeed, professional botanists view the scientific study of plant classifications as a dynamic—not a static—undertaking. Reclassifications are common as botanists learn more about each plant’s structure and DNA. Even recent Bois d’Arc hybrids may one day expand the Maclura Genus.
All wildflower species are seasonal but they usually reappear in the same areas at their appropriate times of the year. Also, most wildflowers prefer disturbed soil; thus they readily take root along many of Rockwall’s paths and roadways. All it takes is a stretch of one’s legs and some careful eyesight to observe Rockwall’s outside florist shops.
Bill McCarron is a retired Texas A&M-Commerce professor who lives in Lakeview Summit.