Terrific Tennessee Trilliums

March 6, 2023  |  Permalink

Sweet BetsyTrilliums perched over Schwoon Spring at Savage Gulf State Natural Area (photo by Holly Taylor)

The long-awaited wildflower season is already in full swing throughout the state! With well over 1,250 species that live and bloom in Tennessee, they can delight us from every trail in our parks and natural areas. The first flush of blooms are what we call the spring ephemerals; species which emerge and bloom from the forest floor before the trees leaf out. These plants live their lives in fast-forward, and are usually gone completely by the time summer arrives. It would take a lifetime to write about each and every one these special plants, so today I wanted to highlight one of my favorite families - the trilliums.

Trillium grandiflorum (photo by Holly Taylor)

Trilliums are unique plants in the genus by the same name. They used to be a part of the lily family, Liliaceae, but were recently given their own family: Melanthiaceae.

While there are over 50 species found worldwide, the greatest diversity of trilliums are found in the southern Appalachian region, with at least 18 calling Tennessee home.

The prefix "tri" refers to the fact that trilliums have virtually 3 of everything: 3 leaves, 3 petals, 3 sepals and reproductive structures in multiples of 3. For this reason it has also been referred to as the "trinity plant."

Trillium flexipes (photo by Holly Taylor)

Other colorful names for trilliums include birthroot, toadshade, wakerobin, birthwort, Indian shamrock, threeleaf nighshade, and American true-love. Many of these have their roots set deep in local folklore, but there are two in particular that I would like to discuss.

Toadshade and wakerobin actually describe two different groups of trilliums with different growth habits, in addition to being whimsical monikers.

While just about any trillium could provide shade for a weary toad, toadshades actually describe the ones that botanists refer to as sessile. These are the plants which have a flower whose base sits directly on top of the whorl of leaves.

Trillium sessile with Virginia Spring Beauties (photo by Holly Taylor)

They also often have attractive mottled foliage remeniscent of a toad's skin.

Wakerobins refer to trilliums with stalked flowers, or pedicellate.

Southern Red Trilliums (photo by Holly Taylor)

There are 8 toadshades and 10 wakerobins in Tennessee, respectively, and they are a diverse tribe of wildflowers.

They range from common and widespread to rare and imperiled, and come in a lovely range of maroon, white, yellow, cream and pink hues.

Let's shine the spotlight on some of these terrific trilliums!

We'll begin with the toadshades.....

Sweet Betsy (Trillium cuneatum) is one of the most common species found across much of the state, but they are most abundant from the Western Highland Rim east to the western edge of the Smokies.

A pair of Sweet Betsy trilliums (photo by Holly Taylor)

The distinctive mottled foliage can vary quite a bit in its pattern, but the plants are typically up to 15 inches tall with leaves up to 7 inches in length. While maroon is the typical color of the blooms, they can also be yellow, bronze or green. The name Sweet Betsy becomes obvious when you kneel down to sniff the flower. They have a spicy, fruity fragrance that is practically mouth-watering!

A park guest stops to smell the trilliums at Rock Island State Park (photo by Holly Taylor)

They are similar in appearance to several other species, so one way to know you have a T. cuneatum is to gently part the petals for a view of the bicolored stamens. If they are blunt-tipped you know for sure you have a Sweet Betsy. 

Blunt-tipped stamens (photo by Marty Silver)

Another common toadshade is the Prairie Trillium (Trillium recurvatum). As its name suggests, this is a primarily mid-western species that ranges into the Southeast.

Prairie Trilliums (photo by Jeffrey Hill)

It also has the distinction of being the only trillium known to occur in the Memphis area along the Mississippi River Bluffs. While at first glance it appears very similar to Sweet Betsy (T. cuneatum), it is typically more slender in its growth habit, and also has recurved (hence the name recurvatum) petals and stamens. They most often occur in large colonies, and tend to bloom a bit later than T. cuneatum.

Prairie Trilliums growing on the Chickasaw Bluffs at Meeman-Shelby Forest State Park (photo by Jeffrey Hill)

Sessile Trillium is another toadshade that could be mistaken for the aforementioned species, but a peek at the beaked stamens and a whiff of its fishy, turned aroma can seal its identification.

Sessile Trilliums bloom alongside Dutchman's Breeches at Edgar Evins State Park (photo by Holly Taylor)

Beaked stamens of Sessile Trillium (photo by Holly Taylor)

This species is found primarily in the middle region of Tennessee.

Trillums rarely bloom alone! Sessile Trilliums alongside state-endangered Blue-eyed Mary (photo by Holly Taylor)

There is at least one other trillium with a pleasant fragrance. Yellow Trillium (Trillium luteum) has a beautiful lemon color and aroma, as well as diagnostic yellow inner parts. This one is commonly found from the Eastern Highland Rim eastward.

Yellow Trillium at Head of Sequatchie (photo by Holly Taylor)

One of the more interesting toadshades is the Twisted Trillium (Trillium stamineum), found primarily on the Western Highland Rim in the western part of Middle Tennessee. This is a species which loves rich wooded areas situated over limestone.

Twisted Trillium (photo by Randy Hedgepath)

It has distinctive maroon flowers with twisted petals that resemble an airplane propeller. 

Even the pistils are twisty (photo by Randy Hedgepath)

They are described as having a "strong carrion odor," so you may want to skip kneeling down for a sniff.

Last but not least, there is one toadshade that is new to science and thus far, unique to Tennessee. In 2014 a population of unique trilliums were discovered on private land in East Tennessee.

Botanists hadn't seen anything quite like them before, and they were given the name Tennessee Trillium (Trillium tennesseense). 

The future of these plants is somewhat uncertain, but hopefully they will be granted full protection in the years to come.

If you ever happen upon a trillium that looks like this while wandering the wilds of Tennessee, please report it to the division of Natural Areas.

Now for the wakerobins. While I love all trilliums, there is something so graceful and refined about the pedicellate trilliums as they nod shyly from their shady sanctums.

(Photo by Holly Taylor)

One of the showiest even has grand in its name: Large-flowered Trillium (Trillium grandiflorum).

Large-flowered Trillium springing from among the similar-looking Sharp-lobed Hepatica leaves (photo by Holly Taylor)

Found in rich, moist decidious woods in the eastern half of the state, T. grandiflorum has wavy white petals that turn pink with age, and bright yellow anthers beaming from their centers.

Large-flowered Trillium watching the hikers go by at Frozen Head State Park (photo by Holly Taylor)

Large, impressive colonies can be found in the rich coves of the Cumberland Plateau and the Cumberland & Appalachian mountains.

Large-flowered Trilliums blooming alongside Wild Blue Phlox, violets and Foamflower (photo by Holly Taylor)

This is one of the few trillliums that is attractive to bees.

A Metallic Green Sweat Bee pollinating Large-flowered Trillium (photo by Holly Taylor)

A white trillium that is common in limestone regions west of the Appalachians is Bent Trillium (Trillium flexipes).

Bent Trilliums (photo by Mark Taylor)

It is distinguished from similar-looking species by its white - pink ovary and creamy colored anthers.

Bent Trillium (photo by Marty Silver)

Its fragrance could be described as a combination of old dirty socks and smelly hound.

Two species that are often confused are the Red Trillium, aka Stinking Benjamin (Trillium erectum) and Southern Red Trillium (Trillium sulcatum)

Stinking Benjamin (Trillium erectum) is not surprisingly one of the more pungent species, often likened to wet dog. It has petals that spread widely, and a purplish black ovary.

Stinking Benjamin blooming amid a flurry of ephemerals (photo by Holly Taylor)

It is a northeastern species that ranges into the Blue Ridge with a few isolated populations on the Cumberland Plateau, and is uncommonly found in Tennessee.

Stinking Benjamin (photo by Holly Taylor)

Southern Red Trillium (Trillium sulcatum) is a bit more common, found from the Eastern Highland Rim to the Smokies.

(photo by Holly Taylor)

The overall flower shape is more cup-like, often likened to a candle snuffer, and the recurved petals tend to overlap one another.

(photo by Holly Taylor)

They aren't always red either. They range in color from deep maroon to creamy white, and smell a bit like mushrooms.

(photo by Holly Taylor)

One of the rarer pedicellate trilliums is found in only a handful of counties in Southeastern Tennessee, preferring upland pine forest. Catesby's Trillium (Trillium catesbaei) has flowers that range from white to pink, turning pink as they age.

Catesby's Trillium (photo by Randy Hedgepath)

The petals are strongly recurved and the anthers spread and curve back as well.

Catesby's Trillium (photo by Randy Hedgepath)

Another of the less common species is the awe-inspiring Painted Trillium (Trillium undulatum) which is restricted to the Blue Ridge Mountains. There is no mistaking those elaborately adorned blooms!

Painted Trilliums (photo by Marty Silver)

Painted Trilliums (photo by Marty Silver)

Trilliums have an interesting life cycle that is utterly dependent on two particular insect groups. When it comes to the blooms, the primary pollinators aren't bees or butterflies. You may have noticed that most trilliums have unpleasant or even pungent odors. These certainly aren't meant to be pleasant to our noses, but they are very attractive to flies.  

A fly checking out a stinky Sessile Trillium blossom (photo by Holly Taylor)

Even the maroon color so often found in trilliums is meant to appear as rotting flesh!

When it comes time to disperse the seeds, an even more fascinating relationship is unveiled.

Trilliums, along with a number of other spring ephemerals, grow an additional structure attached to their seeds called an elaiosome. This fleshy appendage is rich in lipids and protein, and makes the perfect food for an ant colony.

The bright red fruits of Painted Trilliums are meant to attract ants (photo by Holly Taylor)

Ants delve into the berry to remove the seeds and carry them back to their nests. Underground colonies have a room devoted to "trash," where the seeds are discarded after the nutritious elaiosome is separated. This compost heap makes the perfect place for a trillium seed to germinate! This unique relationship is called myrmecochory. 

It is thought that 30-40% of our spring blooming wildflowers depend on this type of seed dispersal.

Ants aren't the only ones responsible for distributing trilliums far and wide. Yellow Jackets have also been documented dispersing trillium seeds.

Like a lot of our ephemerals, trilliums are slow-growers with long lifespans (25 years or more). It takes most trilliums about 7 years to reach blooming age, and they have a limited ability to store energy. This makes picking their flowers very detrimental to the plants. Removing the flower and leaves before it has the chance to produce seed can set the plant back for many years.

Only plants at least 6-7 years old will bloom (photo by Marty Silver)

Needless to say, please never dig up any trillium or other wildflower when you visit your parks and natural areas. If you want to add trilliums to your yard there are a number of native plant nurseries in Tennessee who grow them just for that purpose. 

Trilliums are only one of the incredible wildflowers that can delight you across our biodiverse state. Our parks and natural areas are vital sanctuaries for these plant communities, but even your backyard can be a biodiversity hotspot for native plants! By removing invasive species and introducing a diversity of native plants, your outdoor space can become an integral part of the local ecosystem. To learn more about planting native, check out your local chapter of Wild Ones.

This Spring as you hit the trails, give a nod to the trilliums. They have waited all winter long to greet you.

Trilliums line the trail at Frozen Head State Park (photo by Holly Taylor)

To learn even more about the other trilliums that call Tennessee home, check out Wildflowers of Tennessee, the Ohio Valley and the Southern Appalachians by Dennis Horn et al.