Published in the McAllen Monitor, January 21, 2023
Story and photos by Anita Westervelt, Texas Master Naturalist
The Asteraceae family of plants is often referred to as the daisy family and informally, the sunflower family. It is the largest family of flowering plants with more than 23,600 species of herbs, shrubs, flowers and trees, many of which grow in subtropical habitats like our Rio Grande Valley.
It is also called the Compositae family because of a unique flower structure especially noticeable in the blooms of a sunflower. Each of a sunflower’s yellow petals is a flower, called a ray flower. Each tiny brown dot in a sunflower’s center is also a flower, called a disk flower, making the sunflower a composite of many flowers on a single receptacle – the head where the flowers are borne.
Native common sunflowers, also called mirasol, Helianthus annuus, are typical roadside plants that are especially beneficial to wildlife. They are likely to be blooming during all seasons of the year. Their pollen and nectar are important to insects like butterflies, bees, beetles, lacewings, flies and moths. Squirrels, mice, beetles, Rio Grande turkeys, bobwhite quail and other birds eat the seeds. The flowers and plants are a good source of protein and fat for deer. Chachalacas and rabbits eat the leaves of sunflower plants and rabbits eat the flowers and stalks they can reach and seeds that have fallen to the ground.
Sunflowers are larval host plants to painted lady, American lady, bordered patch and silvery checkerspot butterflies. Dead stalks left standing provide homes for some species of native bees. Sunflowers are long-lived; their root base is helpful in holding soil during windy weather. Spent sunflowers, mowed down and mulched add nutrients and microorganisms to the soil.
An interesting fact for math lovers: the seeds in the center of a sunflower are aligned in harmony with the famous Fibonacci sequence formula.
While native plants are certainly recommended, some introduced species in the Asteraceae family, like Mexican flame vine, Pseudogynoxys chenopodioides, are popular in local butterfly gardens.
Native to Mexico and tropical America, the plant blooms during cold weather. Its vibrant orange flowers attract butterflies, bees, flies and wasps when other plants may not be flowering. Like many native plants, it, too, is drought, heat and wind tolerant.
There are a lot of possibilities with this plant. It is a vigorous climbing and twining vine, ideal for an arbor, trellis, chain link or wooden fence, or planted to grow up porch rails or over and around a personally designed support. Let it trail from a hanging basket or patio pot or plant it to travel up the trunk of a palm tree.
Without support, it forms a sprawling groundcover, running along the ground and rooting between the leaf nodes, which can be potted up to make new plants. It blooms best when planted in full sun; pruning to direct or control growth also increases blooming, otherwise it flowers at the top of the vine.
Dense foliage stays green all year and provides shelter for lizards. The plant may die back at temperatures below 30 degrees Fahrenheit but will grow back from the roots.