Rain Lilies and Hawkmoths

I witnessed the most amazing spectacle in the garden one evening.  I had just finished transplanting a few perennials when I noticed some flying crepuscular creature darting around in my garden patch.  Against the waning twilight of late summer, I could see that it first appeared to be the size of a small bird, but it wasn’t flying smoothly like our avian friends typically do.  No, it had more jerky movements like a grasshopper. And, it was coming my way.

It flew to five feet behind me.  Whirling around, I saw it start to hover and steady itself above the rain lilies that had just opened from the soaking five days prior.  I stood and watched the beautiful dance between hawkmoth and salverform flower.  Flying about six inches above the plant, it prodded and probed to find the entrance, almost like when you try to plug an electrical outlet into the wall in the dark.   

And, then the second surprise of the evening came.  It descended towards the flower to barely an inch above the petals.  The nectary and ovaries were really that deep?!  Wow, I had never noticed that!  I didn’t grow up with Cooperia drummondii (aka Zephyranthes chlorosolen) in west Tennessee, and after transplanting a few last year into my garden, this time was the first I’ve watched them be pollinated.

Finally, it hit me to pull out my phone and record the spectacle.  I watched as it went from flower to flower to flower repeating the same pattern.  The search for the tube, the dive in, and the move on.   I noticed with this first round of feeding the hawkmoth took its time, perhaps spending 15 to 20 seconds or so per flower.  And, the wings and proboscis were so powerful they were moving the surrounding flowers. 

After the hawkmoth had perused the line of Cooperia, it flew off to another white flower in the garden that wasn’t a rain lily as it soon discovered.  As I gathered my tools, I noticed it then returned for a second round, but this time the visit at each flower was only a few seconds.  I suppose the first pass it had drunk the flowers dry.  It flew off into the night, and I headed inside to try to ascertain which hawkmoth friend I had just made.

To my surprise, I learned it was the adult form of the tomato hornworm, the five-spotted hawkmoth. Even though I detest their destructive habits on my tomatoes, I suppose I could start leaving one or two to enjoy the fall feeding frenzy on rain lilies.

Cooperia drummondii flowering approximately five days after a rain. If you look at the bottom of the photo and follow the scape up, you’ll see the ovary where the green fades to brown.

A few weeks later, the seed heads rupture. I collect seed and scatter it to make more plants. If you look closely at the immature ovaries, you can see the wilting tube attached at the top through which the hawkmoth’s proboscis would have descended.

Seems hawkmoths aren’t the only insect that likes to pause at rain lilies.

The Clouds of Pycnanthemum

“Is this thyme?!?”, I remember my teenage mind questioning at the sight of foliage that resembled the herb.  It was March, and I was rummaging through the fencerows near our house looking for wildflowers on a cloudy day that couldn’t decide if it was winter or spring.  Per usual, nothing much was to be seen since I lived in the avoidance zone, but my blitheful, naive self still held out hope I might find something in the leaf litter.  

And, here it was.  I knew enough about herbs to cue in on the small, elongated leaves stooping down.  The foliage looked a bit more pointed than the mother of thyme clump I had back home, but I crushed some, and it released a spicy menthol smell supporting my teenage hypothesis.  “Wow, I’ve discovered thyme from some old homeplace,” I said to the forest around me.

Looking back on the whole experience now, I chuckle.  I didn’t know about Occam’s razor then.  Nor, did I pause to critique my thinking with questions like how has thyme survived in this underbrush, or how has it not spread out and taken over creation?

No, back then I knew thyme wasn’t native to the US; therefore, I assumed someone planted it here.  It still had its low winter foliage just like the herb in my garden. 

So, I transplanted it home and nurtured it.  And, then it started to grow. And grow and grow and grow until it was over two feet tall.  This plant was not thyme! I went through a wildflower book I had and found a match in the Lamiaceae section—Pycnanthemum tenuifolium. 

Pycnanthemum tenuifolium flowering en masse.

Narrow-leaf mountain mint is currently blooming in my garden, and seeing it flourish was a fun reminder that I make mistakes and learn from them.  Sometimes when we are wrong, it turns out better than we could have imagined! Some fifteen years ago in my teenage years I didn’t realize what I had discovered—one of the best native perennials for pollinators and other insects. 

I’ll go ahead and address the white elephant (or, should I say white-flowering herb!) in the room.  Yes, as a “mint” it can spread some, but I’ve never had the issues with it that I’ve had with other Pycnanthemum or Mentha species.  I see having more of it as a good thing.  Even with its vigor, I lost the clump I found along the roadside.  But, a few years ago, I began to hunt for plants for creating floras.  I knew where Pycnanthemum was; therefore, I decided to saunter back along the same fence row in search of it.  After a few hours, I found one inflorescence.  I collected a piece from that Tennessee plant and some seed, and this germplasm became the basis for our plants that we use on campus.   Years later, I would find local Texas ecotypes on the road.  Both are blooming now in my garden and offer so much.  

A haze of Pycnanthemum tenuifolium flowers over a perennial planting at my house.

The fine-textured foliage emerges in tight columns rising upward.  In bud the plant makes me think of the constellation Crux, or the southern cross, for the haphazard dots that attempt to form perpendicular lines.  After flowering I enjoy seeing the seedheads that persist well into winter.  

X marks the spot on Pycnanthemum tenuifolium. Since the inflorescences are cymes, that character likely generates this interesting floral architecture.

But, the flowers are the pinnacle attribute of this plant.  The blooms remind me of stratus.  Instead of countless moisture particles composing a flat, gray-white cloud that blankets the earth, here hundreds of mithril-colored flowers form sheets that hover over the foliage.  These dense flowers are the origin of the name Pycnanthemum (pycn- means dense, and -anthemum refers to the flowers).

And, the insects that flock to this all-you-can-eat-buffet is astounding—bees, wasps, flies, butterflies, and more that I’m missing.  Research has shown Pycnanthemum tenuifolium to be a great niche for beneficial insects from providing resources for native bees to creating habitat for predators and parasitoids.   I’ve observed that the plant buzzes most with activity in the middle of the day.  I have plants near each other to accentuate their seasonality, and for the pollinators it makes cloud hopping even easier.  

A zebra swallowtail waddling through the flowers on Pycnanthemum tenuifolium. Yes, I know you can’t see motion in this still picture, but trust me. It waddled.

A giant swallowtail probed Pycnanthemum tenuifolium flowers.

The other day I took advantage of an overcast sky to take photos of my narrow-leaf mountain mint.   I smiled at the similarity of seeing the dark insects dart amongst the silvery-white flowers and how they resembled the shadows of birds circling above me in a broken, gray altostratus sky.  Both looking for food and both trying to live.  This national pollinator week, I recommend planting this perennial in abundance in the garden so that you, too, can have a richer life and enjoy the clouds of Pycnanthemum and all the life that comes with it.  

Beauty in the Spring

“I’m probably the only person in Texas doing this.  Well, let’s be honest, Jared.  Probably the whole US.”

I chuckled talking to myself as my shovel loosened the eighth clump of spring beauty from a bed in my vegetable patch.  With a sunny afternoon and the return of warmer temperatures, the flowers were beginning to explode and made finding them easier.  I stood up with the transplant, paused to pull off any weeds that still had purchase in the loosened soil, and reached underneath to check and make sure the corm was there and intact.  It was.  

I smiled thinking about someone else moving this plant because who would waste their time relocating these little guys?  Spring beauty by itself isn’t super showy.  The flowers are maybe the size of a dime, and they are finicky opening and closing with the day or rainy weather conditions.  However, looking up at my yard I was reminded why my fingers were coated in the warming winter muck; drifts of pale pink flowers wafted in the breeze.  And, I couldn’t stand the thought of harming any of them, even if this area was where I would be cultivating vegetables.

Claytonia virginica in full bloom gives the appearance of snow. I had plugged some Narcissus in this area earlier this fall, but I plan to relocate them. The yellow is too saturated for the pink tint of spring beauty.

I have adored spring beauty since I first observed it growing in someone’s yard down the road from our house in Tennessee.  I was amazed at this tiny white bloom that abundantly covered their entire front lawn every spring.  Why couldn’t our homeplace look like that?  I didn’t know the plant at first. I kept wanting to stop and look at it more closely to ascertain its identity, but soon I found it growing in a nearby woods and collected a few to take back to my garden.  I had turned an interesting-looking stranger into a friend by finally meeting Claytonia virginica.  

If you drove by recently and saw me laying on the ground, this photograph was why.

The few I transplanted those many years ago don’t even begin to compare with the thousands that now grow in my Texas yard.  I didn’t know they were here when I chose this location for the edible patch, hence my moving them now to a bed that needs more early spring color and vegetation.  I didn’t even know they were here at all when we bought the house in August 18 months ago!  But, when the first frost erased the turf’s chlorophyll and created a mosaic of tans, thin strips of purple foliage caught my eye.  The Claytonia was slathering on some anthocyanins for winter sunscreen.  And, as the winter unfolded into spring, I would see it was everywhere as it came into full bloom.  

In Tennessee this species became my herald of spring and a sign of warmer days to come.  But, here in Texas I have caught it blooming even before the onset of winter.  In 2017 I noted the first bloom on 05 December, and this past year, I caught two separate plants flowering just shy of the solstice on the 16 of December.  As an ephemeral, it must use its 15 minutes on stage wisely to grow, flower and set seed, and store energy before the canopy closes.  After that, the plant vanishes until the show returns next year.  Therefore, it makes sense that through natural selection it start performing as early as it can.  

I’ve learned much about spring beauty in recent years both digging in the soil and the literature.  There is a single corm from which the flowers and foliage arises.  Some sources will label it a bulb or a tuber, but from what I’ve deduced a corm more accurately reflects the circular storage organ.  The flowers grow out and then up from the mature corm, which gives the appearance of the shoots arising in a circle while the foliage tends to emerge straight upwards.  So, if you decide to move some from the lawn, take care not to slice through the shoots.  I like to sink the shovel in the soil on the outside of a clump and lift.  Then, I take care to settle the plant back in to the same depth.  

A single clump of Claytonia virginica nestled into its new home.

I have often thought of spring beauty as the deep south’s alternative for Galanthus.  We have a sparse selection of geophytes due to our lack of chilling.  Yes, the flowers are smaller, but their bloom time lasts longer than snowdrops due to a dozen of flowers on one raceme.  Claytonia virginica also has color variation within a population. You will likely see white-flowering and dark-pink-flowering plants in the same area with color morphs along that gradient. Research done in 2004 sheds light on why. Pollinators prefer dark-pink-colored flowers; thus, with natural selection you would expect to see the population flower color get darker and darker pink over time. If pollinators prefer a color, that usually means more pollination, more seed set, and more individuals expressing that trait in the population. However, the white flowers get their coloration from compounds like quercetin and kaempferol. These molecules protect the plant from herbivory and fungal infection. It’s a really fascinating look at different selection pressures maintaining variation in a population. One plant I moved had darker pink flowers has some rust-like disease on the leaves. Maybe this research explains why!

And speaking of pollinators, since spring beauty blooms so early, it makes a good model species for studying early spring behavior of bugs.  One paper I read demonstrated that 22 species of insects visited the flowers over a two-year observation period.  Filaments (the structures supporting the pollen-loaded stamens) that reflect UV light no doubt light up the runway for our antennaed friends.  Humans used to depend on them, too. A student once taught me that Native Americans once dug them and ate them. 

Claytonia virginica can have different colored blooms in the same population. Here, you see white and pink flowers. Also, notice how pink the stamens are (the five rice-shaped structures near the center of the flower).

It’s been a few weeks since I transplanted the Claytonia, and they are settling in nicely.   I enjoy walking out the door and seeing them a stones throw away.  With spring on the rise, other tasks call for me in the garden, but know that next year when they emerge again, I’ll find loners that need to be relocated from cultivated beds to less disturbed and more permanent plantings.  One day my garden beds will look look a little less barren and like the lawn will be dusted with this spring beauty, too.