Nyctinasty

Quit yer giggling, some of you! "Nyctinasty", or "nyctinasties" in its plural form, is not etymologically based where you're thinking, but on the root word "nastic"; of, relating to, or constituting a movement of a plant part caused by disproportionate growth or increase of turgor in one surface.  "Nyctinasty", a new word for ProfessorRoush's vocabulary, is the term for the circadian movement of plants (such as the closing of flowers or reorientation of a leaf position) that occurs in response to changes in light intensity and temperature.  This circadian rhythm is carried out by by a special organ in some plants named the "pulvini", a swelling at the base of a petiole or petiolule.  

For those "in the know", as you now are, nyctinasty differs from tropism, which is the term for plant movement in response to growth stimuli, such as when sunflowers follow the sun.

'Prairie Moon' at night

I was prompted to look up and learn the proper label for the phenomenon because I noticed for the first time, that when the peony 'Prairie Moon' blooms, it closes its flowers each evening; something I learned out of frustration one night when I thought, "hey, 'Prairie Moon' is probably blooming at its peak and I should get a picture and blog about it."  Needless to say, I learned something new that very night about this cultivar after its many years in my garden, and I had to go back the next morning to photograph its open and voluptuous blossoms.   The photos here in this blog entry were taken the same day; the "open" photos at 3:25 p.m. and the "closed" at 7:38 p.m.   Interestingly, in my blog about 'Prairie Moon' on 5/3/2023, there are photos of both closed and open states, but I was evidently curiously incurious about the process then.

If you read the Wikipedia entry for nyctinasty, it will veer into a sleep-inducing paragraph of phytochromes and protein Pr and PFr states and potassium gradients, but all those subcellular processes add up to the fact that in the pulvini, water moves into the lower cells (ground-sided), swelling them and closing the petal. Wikipedia also tells me that an alternative mechanism exists through hydrolysis of bioactive glycosides.  I am fortunate to have a scientific education that helps me understand all this, but I am also fortunate that understanding the process doesn't diminish the wonder and "awe" of it for me.  "The heavens declare the glory of God; and the firmament showeth his handywork": Psalm 19:1 KJV.

'Prairie Moon' midday

Online sources theorize that nyctinasty is likely a response to preserve pollen, decrease nightly predation, and minimize temperature decreases and water loss at night.   It occurs in many plants, but I haven't see Paeonia listed among those.  Most legumes close their leaves at night.  Flowers that close at night include daisies, California poppy, Lotus, Rose-of-Sharon, Magnolia, Morning glory, and Tulips.  Some flowers, pollinated by moths or bats exhibit nyctinastic flower opening at night (for example the Nicotiana).

Anyway, now you know.  If you're looking for me at dusk, at least for a few weeks, you'll find me in the garden looking for nyctinastic behavior in other peony species.  I think 'Prairie Moon' may be unique in that respect, at least in my garden.

Truncated Spring

Merely a few weeks back, on March 14, I wrote a blog full of hope for a gradual and beautiful Spring. "Irrepressible Spring", I titled it.  At the time, we'd had warm weather and it looked like everything was in place for a gradual, unprecedented garden year.  The plants were all greening and budding up.  Redbuds and lilacs looked like I've never seen before.  To borrow the style of our current President, "no one in Kansas has ever seen anything like it before, it was going to be spectacular!" 

It turns out that Spring can he suppressed. Now I'm reminded of Euripides; "Deus quos vult perdere, dementat prius", which Google translates as "God first drives mad, those he wants to destroy."  One very cold night about two weeks ago, as in my last blog, my hopes turned to dust, to browned buds of yet-unborn flowers and shriveled leaves. Early growth on the roses was wiped out, daylilies were killed down to the ground, and most buds on lilacs browned and fell off.  My redbuds never bloomed, nor did the forsythia to any great degree.  The bloom of Magnolia stellata I featured in the previous blog is, alas, the only one I am to see or smell this year.  To give you some idea of the losses, the picture at left is Magnolia 'Jane' just 3 days ago, a few stray buds blooming near the ground, nearly every other bud on the bush a dried and shriveled husk. 

Of all my lilacs, only 'Declaration', a Syringa hyacinth cultivar, bloomed in any abundance, an entertaining treat to the bumblebee as pictured above.  Three or 4 years old, it struggles in a dry summer, but is now repaying my efforts to periodically give it some extra water.  I'll gladly accept its tribute to my toils.

Paeonia tenuifolia, the Fern-leaf Peony, survived the cold, which didn't surprise me now because I know the delicate foliage hides a resilient nature.  A month ago, this clump was 6 inches high and the new foliage felt like velvet, its promise still curled against the cold.  Now it blooms alone in my front landscape; a bright red remedy for a broken heart.  

Of all my Magnolias, only the blooms of tardy 'Yellow Bird' survived the frozen night.  Now, it lights up the back yard, the only sign of its struggles perhaps that its yellow hues are a little lighter  than in previous years, at least it made it through the cold.  A lot of my Spring optimism rides with 'Yellow Bird' each year, so I'm thankful to see that its delayed timing strategy worked once again.

Now, I bide my time, waiting to see what recovers; to discover what will develop and flower normally and what may still yet be affected.  The peony, rose and daylily seasons come in rapid waves of succession soon, and, chastened, I hold no anticipation now that all will be normal in the year to come.  I merely will wait and hope the garden will provide.