Resilient Ruellias

Ruellias flower throughout the heat of summer.

Are you looking for native, non-aggressive flowering plants that are perfectly adapted to our central Texas limestone soils and extreme summer heat? Then look no further than some of our local species of Ruellia, also informally but incorrectly called wild petunias. They include Drummond’s Ruellia (Ruellia drummondiana), Hairy Ruellia  (Ruellia humilis), Metz’s Ruellia (Ruellia metziae), and Violet Ruellia (Ruellia nudiflora).

Drummond's Ruellia

A Texas endemic, Drummond’s Ruellia has ovate, fine-haired leaves and purple to dark lavender stalkless (sessile) blooms arising from the leaf axils (axillary). It is prominent on the Edwards Plateau and in and around Austin, and blooms from June to November. Hairy Ruellia, also called Fringeleaf Wild Petunia, has conspicuously hairy oval leaves with pointed tips and hairy margins, and purple to pale purple axillary, sessile blooms. It is highly drought-tolerant and is widespread in open prairies on limestone soil, where it blooms from May to September.

Hairy Ruellia

Metz's Ruellia

Metz’s Ruellia or White Ruellia is distinct in that it features uncommonly white or pale-throated stalked (peduncled) blooms in a branched structure (panicle) at the tops of stems (terminal), and oval leaves on long leaf bases (petioles). It thrives on limestone outcrops and in open woods, and blooms from June to August. Violet Ruellia, also called Common Wild Petunia, is one of the most ubiquitous of all these species, with a similar arrangement of peduncled blooms in a panicle on the terminal ends of stems, but the blooms are purple to violet-blue. The leaves are oval, smooth and essentially hairless (glabrous) with somewhat wavy margins, and the blooms occur from April to October.

Violet Ruellia

Mexican Petunia (non-native)

Unlike the invasive, non-native Mexican Petunia (Ruellia simplex) that is sold in many nurseries, these resilient native species are well-behaved. They provide a bounty of successive summer blooms while other flowering plants are wilting in the heat. Their flowers open in the morning and fall off by evening, and they can be correctly identified by the structure of the inflorescence (axillary or panicled), leaf texture (waxy, hairy, or fringe on margins) and leaf shape (ovate, oval, or lance-shaped). The Hairy Ruellia and Violet Ruellia species are also host plants for Common Buckeye and White Peacock butterflies.

The genus Ruellia was named after a French botanist and physician, Jean Ruelle, who lived during the Renaissance Period. He was noted for his 1536 publication in Paris of De Natura Stirpium, a Renaissance treatise on botany, which included detailed descriptions not only of a plant species' habit and habitat, but also the smell and taste of each.

Brooding Butterflies

 

Common Sunflower is a native larval host plant for one of our brooding butterflies. 

In human terms, brooding typically means showing deep, quiet unhappiness but when it pertains to butterflies, it describes how many broods or distinct generations of butterflies a species produces in one year. Summertime in our area highlights those butterfly species that have multiple broods spring through fall, also called multivoltines. The most commonly seen multiple brooders include Queen (Danaus gilippus), Gulf Fritillary (Dione vanillae), Bordered Patch (Chlosyne lacinia), White-striped Longtail (Chioides albofasciatus), and Pipevine Swallowtail (Battus philenor) butterflies.

Queens are most often confused with Monarchs, given their mostly rich orange-brown coloring, with white spots nearest the wing tips and in the black wing margins, but lacking the Monarch’s bold black wing veining. Like Monarchs, their native larval host plant is milkweed, specifically Antelope Horn, Fringed Twinevine, and Butterfly Milkweed.

Queens are often mistaken for Monarchs.

Gulf Fritillaries are another mostly orange butterfly, with a few black markings on the wings above and many elongated silvery spots on the wings below.  They have slightly elongated wings and their flight is fast and usually well above the ground. Their native larval host plant is passionvine, including Purple Passionvine, Fetid Passionvine, and Yellow Passionvine.

Gulf Fritillary nectaring on Blue Mistflower.

Silvery spots on the underside of the Gulf Fritillary.

Bordered Patches can be remarkably variable, but typically have black forewings and hindwings with an orange and/or creamy white median band of spots that can vary in width. Their native larval host plants are in the sunflower/aster family, specifically Common Sunflower, Cowpen Daisy, and Black-eyed Susan.

Bordered Patch on one of its native larval host plants, Cowpen Daisy.

White-striped Longtails are brown butterflies with very long tails and a prominent white stripe on the hindwing below. This characteristic is usually easy to see since these butterflies typically perch with their wings closed. Their native larval host plants are legumes in the pea family, namely Panicledleaf Ticktrefoil and Softleaf Mimosa.

White-striped Longtail nectaring on Blue Mistflower.

Pipevine Swallowtails are our most familiar dark swallowtail, black above with a single row of pale spots near the wing margins. Males have a beautiful blue-green iridescence on the hindwing above, and both sexes have a single row of bright orange spots in an iridescent blue background on the hindwing below. Their native larval hosts plants are pipevines, including Swanflower and Virginia’s Dutchmanspipe.

Upperside of a male Pipevine Swallowtail.

Underside of a Pipevine Swallowtail.

These multiple brooders produce three or more continuous generations per year, often flying repeatedly from early spring to late fall. The final brood of the year often exhibits different physiological or behavioral traits, such as delayed development or seasonal movement, that allows them to survive winter conditions. In the case of the species outlined above, most move further south as the temperatures fall and then north again as they rise, but the swallowtails overwinter hidden away in chrysalis form until warmer temperatures coax them to emerge in spring.