Wildflower Wednesday: Necklace gladecress (Leavenworthia torulosa)

Leavenworthias, generally known as gladecresses, are late winter rosette-forming annuals with the sweetest little flowers. Our Wildflower Wednesday star is Leavenworthia torulosa and could easily be mistaken for another of the Leavenworthia  found in middle Tennessee. What made identifying this species from the others was the necklace/chain of beads' pod holding the seeds.

 

the necklace seed pod for id

 Gladecresses are members of the Brassicaceae/Mustard family and have a few iconic features.

• Usually herbaceous plants    
• 4 petals form a cross     
• Fruit: a pod or a capsule that is either a long and slender pod (silique) or short and broad pod (silicle)
• Flowers usually have 6 stamens (male flower parts), 4 tall and 2 short 
• Flowers are usually yellow, white, orange and lavender
  

 There are eight species of Leavenworthia native to the southern and southeastern USA. Four are native to Middle Tennessee.

1. Leavenworthia alabamica  
   
2. Leavenworthia aurea
3. Leavenworthia crassa
4. Leavenworthia exigua (TN)   
   
5. Leavenworthia stylosa(TN)
6. Leavenworthia texana
7. Leavenworthia torulosa(TN)
8. Leavenworthia uniflora(TN)

 Ecologically they are plants that are restricted/endemic to Cedar Glades in middle Tennessee, limestone glades and other thin-soil areas where limestone bedrock is at or near the surface. 

 

The winter wet seeps are a perfect growing medium for our star and other Leavenworthia. They tolerate growing in standing water and disappear before the extremely hot and dry summer conditions that you inevitably have where soil is thin and limestone is close to the surface or exposed.

I discovered our Wildflower Wednesday star about a dozen years ago growing in a wet depression in a sunny field/lawn not too far from my house. Being wowed doesn't begin to describe how excited I was to discover them. It was late winter/early spring and the ground was incredibly soggy. At first there were one or two flowers but, as the days warmed up more flowers opened and they made a lovely ground cover.  

 I am thrilled that the small population hasn't disappeared. They're winter annuals and once the flowers are pollinated and seeds develop in that necklace like pod they get dispersed in late spring/early summer, then germinate in the fall, and individuals overwinter as little rosettes before flowering begins in the early spring (from Baskin and Baskin).

Fortunately, all that's completed before spring and summer mowing begins.

Although, Hillwood, my neighborhood in Nashville, is not in a cedar glade, it has many areas of shallow soil and exposed limestone; including my property. Which make it attractive for many plants that would also be found in a glade. Unfortunately, the seepy area in my habitat is in the shade and there are no Leavenworthia.

The particulars

Botanical name: Leavenworthia torulosa

Common name: Necklace gladecress

Family: Brassicaceae

Species description: Annual

Habitat: Cedar glades, pastures, seepy areas, thin soil over limestone beds, roadsides, old fields Tennessee, Alabama, Georgia (?) and Kentucky.

Bloom: Late winter, February through April

Size:  About 3-4 inches tall. 

Bloom Color: White, yellow, lavender 

Comments: It's considered common in Tennessee because of the abundance of habitat, but, habitat is disappearing fast with the growth in middle Tennessee.

Propagation: Seeds are pollinated and then dispersed during late spring and early summer, they germinate in the fall, and individuals overwinter as quiescent rosettes before flowering begins in the early spring (Baskin and Baskin) Go here for MOBOT's research on plant adaptability. I don't know of any seed sources.

Wildlife value: I've done a pretty deep dive and have seen a few mentions of small bees and honeybees visiting gladecresses, but, L torulosa is self-compatible/self fertilizes, so it doesn't rely on pollinators. Researchers say that this can mean smaller flowers. Pollinators or not, they are really cute little flowers.

click for source

If you live in Middle Tennessee I urge you to visit a Cedar Glade.

 I fell in love with them on my first visit. It has a beauty that can't be easily defined. It requires one to look closely at the ground to see small plants like Leavenworthia, Sedum, moss and lichens; while remembering to look ahead to see the huge expanses of exposed limestone and to the shrubs and trees at the edges of the glade. 

Historically they've been unappreciated and used as quarries, parking lots and dumps.

 

They're botanically unique ecosystems with rare and beautiful plants. One of my favorite times to visit is late winter when the seeps, wet swales, or ephemeral streams are flowing and Leavenworthia are blooming in the standing water. But, early summer is another great time to visit when you'll see the  Tennessee coneflower following the sun. I think you will be enchanted by the glade's stark beauty. I always feel awe when I'm there.

xoxogail

 

Welcome to Clay and Limestone's Wildflower Wednesday celebration. I am so glad you stopped by. WW is about sharing and celebrating wildflowers from all over this great big, beautiful world. Join us on the fourth Wednesday of each month. Remember, it doesn't matter if they are in bloom and, it doesn't matter if we all share the same plants. It's all about celebrating wildflowers. Please leave your url when you comment. I love your comments, so thank you for leaving them.

Gail Eichelberger is a gardener and therapist in Middle Tennessee. She loves wildflowers and native plants and thoroughly enjoys writing about the ones she grows at Clay and Limestone. She reminds all that the words and images are the property of the author and cannot be used without written permission.