Anita’s Blog – Silverleaf Nightshade Report
- jjvanm
- Sep 29
- 5 min read
The first thing I learned about silverleaf nightshade, Solanum elaeagnifolium, was that bobwhite quail eat the seeds.
Bobwhite quail calls like coyote songs these days seem to be far and few between; if a native plant is good quail food, I’m all for it. But there’s more to that story.
Noticeable along roadsides on these late summer days are great swaths of the lavender blooms and silvery green foliage of silverleaf nightshade. It is a native plant, but it has some negative tendencies that might change my mind about my being so elated when I see it in all its abundant splendor. And not just because it seems awfully dangerous to expect quail to have to eat their meals so close to a heavily travelled road.
Silverleaf nightshade is a sturdy, upright plant, about 12-24 inches or more in height with fine, star-shaped white hairs on the leaves that create the silvery effect. The flowers are like a five-point starburst about an inch in diameter; their blooms are in clusters with dark purple to pale lavender petals with yellow nectar guides and yellow stamen. Sometimes the petals are white.
The flowers are quite beautiful.
The fruit is a small, yellow berry that turns black. The ripe fruit is toxic to animals, although bobwhite quail and other birds can eat the fruit and seeds.
Here’s where I began to change my mind about being excited about this particular plant: A Texas A&M AgriLife Extension online publication, “Virtual Herbarium Plants of Texas Rangelands,” notes that silverleaf nightshade is a serious weed of prairies, open woods and disturbed soils in southwestern United States and Mexico.
Many native plant publications mention where described species might be found, like along roadsides, adjacent to agricultural fields or in disturbed ground. I might be going down a rabbit hole, but I was curious to know just exactly what defines disturbed ground. Certainly, I can use my imagination, but I was surprised to find such thorough answers on numerous Internet websites that explained what, in the habitat world, constitutes disturbed ground.
Disturbed ground or disturbed soil is earth that has been physically or chemically altered from its natural state by human activity, according to information from the U.S. Forest Service. That activity can be something as simple as gardening or landscaping. On a massive scale, it includes clearing vegetation, digging, trenching, and excavating land for construction or building roads and utilities, all of which disrupt soil structure and create altered ground.
Agriculture also creates disturbed ground: plowing and applying fertilizers or pesticides can change the physical and chemical makeup of the soil. Weather and natural processes can disturb the ground, too, such as animal activity, freeze-thaw cycles, wind action, downhill creep of soil on slopes and floods can cause ground to be disturbed, which, over time, can reduce function.
When soil is disturbed, healthy microbial populations and organic matter are disrupted, perhaps destroyed. Disturbed soil often lacks biological richness, ending in reduced ecosystem function.
On the other hand, undisturbed soil is soil that remains in its original, intact form.
What does all this have to do with silverleaf nightshade and quail?
Silverleaf nightshade, native to and widespread throughout South Texas, is a very adaptable, resilient plant that thrives in a diversity of soil types in dry, semi-arid conditions of the Rio Grande Valley. That description actually seems to give the plant a lot of positives. Quite the opposite, though.
Despite its native status, silverleaf nightshade is prone to behave aggressively (wildflower.org's phrase), especially in disturbed soils.
The species has deep taproots, to begin with, so it heartily regrows from the root system. Silverleaf nightshade also reproduces by creeping root stalks and seeds. Each growing season, depending on environmental factors, an individual plant can produce in excess of 200 berries, each containing between 24 and 150 seeds, according to a Boyd & Murray 1982 study in a Weed Research journal at Wiley.com.
Once established, silverleaf nightshade is extremely difficult to control by herbicide or hand-pulling, it has deep rhizomes that break easily and readily resprout and generate new plants from small root fragments.
In addition, mowing silverleaf nightshade only makes it stronger, according to an interesting June 2024 weblog, Botany One, which cited a mowing experiment conducted at the University of Texas Rio Grande Valley near Edinburg. “Frequent mowing (in its native range) can trigger defensive responses, making the plant more resilient and hardier, with deeper roots and spikier stems, and giving it an edge over other plants in disturbed environments,” read a study by Alejandro Vasquez and colleagues, published in “Scientific Reports.”
Silverleaf nightshade is found in more than 40 countries and listed as highly invasive in more than 23 countries. From South Texas to South Africa, Australia, India, Greece and beyond. It is considered an agricultural pest, infesting fields and reducing the yields by competing with water and nutrients, in crops like cotton, corn and sorghum, according to a National Cotton Council study.
Its ripe berries especially are toxic to animals, although, as mentioned, a number of birds can eat the fruit and seeds. Nightshade plants belong to the Solanaceae (potato) family of plants; most are toxic; the primary toxin is solanine. Other common names for silverleaf nightshade are white horse nettle, trompillo, tomato weed and bull nettle.
As for bobwhite quail, there is so much more available for them to eat than silverleaf nightshade, which by the way, hardly measures as a percentage of their diet. Bobwhite quail are omnivores and granivores. They will eat plant-based foods, seeds, leafy, green vegetation and animal-based food, such as insects, like beetles, sawflies, wasps, bees, ants, grasshoppers, crickets, roaches, spiders and scorpions. Cultivated crops, especially milo and millet, are good; forbs, including cow pen daisy, crotons; and woody species, like mesquite, prickly pear, wolfberry, mimosa, and hackberry all provide calories, moisture and nutrients.
An excellent online publication that came to my attention while researching bobwhite quail is at the following link. Page 2 has a nice comprehensive list of quail food, if that’s your interest.
“Bobwhite Quail Management in South Texas” online publication https://tpwd.texas.gov/publications/nonpwdpubs/quail_management/Managing_quail_in_south_Texas.pdf
If you’re trying to get rid of resilient, but pesky silverleaf nightshade, you may find this helpful:
Texas A&M AgriLife Extension “Weed Busters” online publication https://southtexasrangelands.tamu.edu/files/2020/08/L5463_WB_Silverleaf-Nightshade_7.20.pdf
Remember how we were taught to find the good in someone? In that vein, I’ll end this account with this: silverleaf nightshade does help quail. The plant’s aggressive growth and deep roots mean it can provide food in drier areas and seasons when other plant life is scarce.
These sites also provided interesting information in the writing of this blog post:
Sciencedirect.com, the conservation foundation.org, Environment Protection Authority Victoria, pollution.sustainability-directory.com, aggie-horticulture.tamu.edu, ams-samplers.com
