Latin for Gardeners June 2026: Fringed Wild Petunia

Latin for Gardeners
June’s Native Maryland Plant

Ruellia humilis Nutt.
(roo-EL-ee-uh HEW-mil-is)
Common Name: Fringed Wild Petunia

June is pollinator month, a time to celebrate and acknowledge bees, butterflies, moths, hummingbirds, and all other creatures that pollinate many of our food crops, help sustain flowering plants and are fundamental contributors to the food web. It’s also a fine time to plant native plants to help support these essential creatures.

One plant that helps pollinators during summer and through early fall is Ruellia humilis, an herbaceous perennial that grows best in sunny, dry to average areas in a garden. The trumpet-shaped flowers have five rounded flared lobes that resemble petunias, hence the common name. The flowers are open for just a day, but the plant will bloom all summer and once established, it is tolerant of heat, humidity, and drought. This plant has simple, opposite leaves that grow in pairs on its highly pubescent square stems.

A notable feature of this plant is the visual pattern on its petals that directs pollinators to the center of its bloom, like a bullseye. Known as ‘nectar guides’, these markings help insects land efficiently, quickly reach the pollen and ensure the plant gets pollinated. In some plants nectar guides are invisible to humans but remain visible to insects because they reflect ultraviolet (UV) light. Bees see colors on shorter wavelengths than humans, they see combinations of green, blue and ultraviolet light, whereas humans see variations of red, blue, and green.

This plant provides both nectar and pollen and is a host plant for the Common Buckeye butterfly. Common visitors are sweat bees that seek out the pollen, and long-tongue bees that can reach the nectar deep within the flower’s tube. Some bees will perform ‘nectar robbing,’ by circumventing the tube opening and avoiding any contact with the pollen. They create a slit in the tube, allowing them to access the nectar without pollinating the plant.

Speaking of Buckeye and Bullseye reminds me that it is tick season. I hope you all take precautions and always check for ticks after walking in the woods or tall grass. If you find a ‘bullseye’ on your body, it’s likely the result of a tick bite and a hallmark sign of early Lyme disease. In my experience, prompt treatment with antibiotics proves very effective in treating this bacterial infection.

NOTE: Ruellia humilis is rare in Maryland. A more common Maryland native petunia is Ruellia caroliniensis. R. caroliniensis is often found in woodlands, preferring partial to full shade and moist to average, well-draining soils.

Alison Milligan – MG/MN 2013
Watershed Steward Class 7/Anne Arundel Tree Trooper
Chesapeake Bay Landscape Professional (CBLP)
alison@lifewithnativeplants.org

Latin for Gardeners: March 2026

Latin for Gardeners
March’s Native Maryland Plant

Viola sororia Willd.
(vy-OH-la so-ROR-ee-uh)

Common Name: Common Blue Violet

Some native plants are more vigorous than others, they’re known to spread into areas where they were never planted and often where they’re unwanted. On occasion I hear these native plants referred to as ‘weeds’ or ‘invasives’ which is, of course, not true. One of these plants is the common blue violet, a low- growing, native wildflower, with dark blue to violet flowers that appear in early spring – a plant familiar to most home gardeners.

When I think about what people ask for when they want me to recommend a new plant for their yard, I often hear things like: “I want a short plant”, “I want vibrant color”, “I want to support bees”, “I need a plant to compete with my weeds”, “I want a long blooming plant”, “I’d like to plant something I can eat”, “I want a spring-blooming plant”, “I want a plant that fits a small budget”, “I want a butterfly host plant”, “I want a plant deer won’t kill”, “I need a plant that can survive under my walnut tree”, “I want a low-maintenance plant to suppress weeds under my shrubs”.

As it turns out, common blue violet fits all these criteria - but there is a caveat: these plants are incredibly fast spreaders and can colonize an area quickly – if conditions are right. In fact, they’ll even grow where most plants won’t tread – like in sidewalk cracks.

Violet’s successful colonization of areas is driven by its ability to spread by 1) fleshy, underground rhizomes 2) ant dispersal (aka myrmecochory,) and 3) by another more interesting method – it’s like a superpower. In late summer, Viola sororia produce hidden, non-opening flowers that sit on the surface of soil. These cleistogamous (1) flowers can self-pollinate and they can eject their seeds up to 9 feet away! This is why violets are often considered a nuisance plant by homeowners trying to maintain a pristine, manicured lawn where violets have taken up residence – they are not easily controlled.

In spring, as I begin to see the true invasive plants that are trying to take hold in my yard and elsewhere, I welcome Viola sororia. Plants like mugwort (Artemisia vulgaris) and lesser celandine (Ficaria verna) are true bullies, harmful plants that will suppress native ephemerals; the latter has leaves that can be confused with Viola sororia. Understanding the colonizing nature of common blue violets and the many benefits it provides to the environment, makes me appreciate it more and even employ its assertive behavior as a deterrent against some of these truly invasive plants. Confronting invasives in a garden is not an easy matter – Viola sororia is one plant that can help, and it looks beautiful doing it.

1) small, non-opening, self-pollinating structures that allow plants to produce seeds without pollinators

Alison Milligan – MG/MN 2013
Watershed Steward Class 7/Anne Arundel Tree Trooper
Chesapeake Bay Landscape Professional (CBLP)
alison@lifewithnativeplants.org

Latin for Gardeners: February 2026

Latin for Gardeners
February’s Native Maryland Plant

Kalmia latifolia L.
(KAL-mee-ah lah-tih-FOH-lee-ah)

Ready to “spring” into action? This Kalmia latifolia will be getting ready to do just that – in May. Mountain laurels have a unique method of ensuring cross-pollination – their anthers (1) , coated in pollen, are positioned under spring-like tension. When a pollinator visits, it inadvertently releases the tension, causing both the anther, and thus the pollen to be forcefully released. Freshly coated in pollen, the pollinator moves on to the next flower, spreading the pollen on its stigma (2) . This catapult-like mechanism is just one of the wonders of a shrub that is known for its evergreen leaves and ability to grow in deep shade.

Mountain laurels are treasured plants in Maryland – their late spring blooms are a welcome sight in their preferred habitat - acidic woodland forest. Planted in too much shade they will have reduced blooms and can become spindly and even gnarly, adding another dimension to their attraction, IMO. The county of Laurel was named for the abundance of laurels in the area, and in Crownsville, MD you can find both a community on a ridge and a court, named for them. But K. latifolia can also be right at home in a backyard setting – if the conditions are right. This plant thrives in well-drained, moist, acidic soil, in partshade. The plants in my yard are on a north-facing slope in part-shade; here they stay cool, even on some of the hottest days of the year, and their unique and exquisite blooms are a welcome site to myself and the many pollinators who enjoy visiting them.

I’m getting ready to ‘Spring Into Action’ at the WSA conference this month. I hope to see many of you there. In the meantime, I’ll have to be a bit more patient to capture the spring action of the Mountain Laurel.

Alison Milligan – MG/MN 2013
Watershed Steward Class 7/Anne Arundel Tree Trooper
Chesapeake Bay Landscape Professional (CBLP)
alison@lifewithnativeplants.org

Latin for Gardeners: January 2026

Latin for Gardeners
January’s Native Maryland Plant

Quercus palustris (Münchh.)
(KWER-kus pa-LUS-tris)

Quercus palustris are one of the very fine red oak trees that are commonly planted and easily recognized along roadways, in resident landscapes and even in parking lot islands – and for good reason. This plant is fast-growing, it tolerates urban stress, pollution and many soil conditions. Of course, being an oak it’s also a major contributor to the food web – its leaves are eaten by a vast number of insects (think very hungry caterpillar) while its acorns feed many other animals – including the very hungry squirrels in my yard.

The only notable exception to the plants’ toughness is its intolerance of alkaline soil which reduces its ability to take up iron, causing iron chlorosis 1 . New growth will generally exhibit the most obvious symptoms, yellowing of the leaves, since without iron the plant can’t produce chlorophyll. The best way to avoid the condition, which can be fatal, is to not plant a Q. palustris in soil that tends towards alkaline (pH 6.5 or below is preferred). If chlorosis is observed and you can manage it, you can take advantage of another strength of this tree – it’s highly transplantable so it can withstand being moved to a more suitable acidic location.

Pin oaks can be seen at the Patuxent Research Refuge in Prince George’s county Maryland. It is the only National Wildlife Refuge in the country established to support wildlife research.

The refuge is a wonderful place to visit in the winter; there are many trails to explore and experience the wonders of the season. The Visitor Center is a destination itself, with many interesting exhibits. This month they’re featuring a photo exhibit by David Jonathan Cohen titled “In the Galápagos Islands”, a place where you’ll find unique plants and animals but no Quercus palustris.

1) Iron chlorosis is the result of a lack of iron in the new growth of a plant. Iron is not necessarily deficient in the soil—it may be there, but just in an unavailable form for absorption through the root system.

NOTE: Bur Oak (Quercus macrocarpa) is one of the oaks that is tolerant of highly alkaline soils and drought. It was featured in January 2025’s Latin for Gardeners’.

Alison Milligan – MG/MN 2013
Watershed Steward Class 7/Anne Arundel Tree Trooper
Chesapeake Bay Landscape Professional (CBLP)
alison@lifewithnativeplants.org