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Category Archives: Baldwin’s Eryngo

Tricky Tick Trefoils

04 Oct

(The pod sticks like a tick. Trefoil refers to the trifoliate leaves)

Desmodium tortuosum and so many more species

Fabaceae

This weekend’s botanical joy has been a study for plant physiology class of the leaf movements by Desmodium leaves to light changes and biological rhythms. Boring to most folks no doubt, but one of the tricky treats we all can see in this back yard marvel. The leaf bases have muscle power, true of most legumes and big-time in Desmodium. The leaf-muscles are called pulvini (pull-VINE-ee), and wiggle-waggle the leaf blades up and down in response to the plant’s wants and needs.

Flowers and segmented pods (John Bradford)

Flowers and segmented pods (John Bradford)

Anybody with socks or pant cuffs knows Desmodium for its laundry fun. The segmented flat pods cling to fur and fabric with hooked hairs like Velcro.   Although a hiker’s nuisance, it’s quite an evolutionary trick to take a flat “peapod,” segment it into break-apart pieces like a Kit-Kat bar, and give them stick-o-rific hairs. I find that as amazing and awesome and phenomenal as any ol’ orchid flower, but sadly there are no Desmodium Societies to join.

desmodium loment

Possibly the beggar-lice helped make Desmodium such a successful genus, with some 300 species around the world, with two dozen in Florida a mix of native, introduced, and of ambiguous nativity. Anything that clingy gets around, and how much of that travel over thousands of years is “natural” is impossible to say. Weeds is weeds.

Just to narrow the field, let’s zoom in on a big one, “Florida” Tick Trefoil, Desmodium tortuosum. The book in front of me deems it not native, but other authorities place its “natural” origins as close as Cuba, and who’s to say those pods don’t sometimes cover the 90 miles without human help! So let’s not be overly dogmatic.   In any case, humans sure have moved it around the southern U.S. quite a bit on purpose.

Here’s a case of why flip-flopping with Mother Nature is not always wise. A couple generations ago the species was “good”—even planted.   It smothered weeds. It fixed nitrogen. It was a green manure, a cover crop, living mulch.   It succeeded…opps, a little too well.

Modern Dixiemodium tortuosum tortures agriculture. (The “tortuosum” refers to the twisted pods.) It is arguably the #1 peanut weed in Georgia, prompting lots of herbicide spraying. I wonder if any gets into the Skippy. Desmo-tort pesters peanuts something awful. I just read that a single specimen about 2 feet from a peanut plant can diminish the yield by almost 20%, and just 8 desmodiums per approx. sq. yard can cut peanut production by over a third.   That’s a serious weed, and it gets in the way of adding fungicides. Farmers are lucky that Dixie Tick Trefoil is one of the few annual Desmodiums, rising up during late season growth. Certain herbicides can be timed to pass over the early-growing peanuts and to suppress the later-maturing Desmodium.

Let’s end on a more colorful note.   A curious aspect about Desmodiums is mixed flower color, even on single individuals, the combo usually being lilac flowers mixed with blue-ish blossoms (as well sometimes as white).  This link shows a mix on the same inflorescence   TRIP HERE and look closely.

Mixed colors are not rare in plant species, and are generally interpreted as a signal to pollinators conveying the reproductive status of the flower, let’s say nectar availability.   It would be reasonable to regard the changes as mere floral age, but some Desmodium species take it a step further.   The flowers have a tippy landing platform with the anthers and stigmas concealed until a bee lands, fairly standard for many legumes.   In Desmodiums, the penetrating bee “trips” the flower on a one-time basis like a rat trap.   The tripped flower pulls the trigger on the color change: “attention pollinators: this flower is taken care of, so go find another.”

 
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Posted by on October 4, 2015 in Baldwin's Eryngo, Desodium

 

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Baldwin’s Kissing Comfit

03 Oct

Baldwin’s Eryngo

Eryngium baldwinii

Apiaceae

Today John, John’s wife Dee Staley,  and George enjoyed a field trip on a perfect October day to the Kissimmee Prairie State Park with the Palm Beach Chapter of the Florida Native Plant Society.  On the way, Dee pointed out  Crested Caracaras to add delight to the day.  Sorry, no pictures!

Although the main theme of the expedition was hot and heavy grass-watching, one of the first distractions was Baldwin’s Eryngo sprawling  in a sandy meadow displaying its fuzzy little blue flower globes.  This species creeps around most of Florida and a little in neighboring states, often on seasonally moist sands.

Baldwin's Eryngo in Kissimmee Prairie State Park. Photo by JB.

Now for a momentary edifying sidetrack.  Ever wonder why so many plants of the Southeastern U.S. have Baldwin in their names, usually as  baldwinii?— Eryngium bladwinii,  Eleocharis baldwinii,  Scleria baldwinii,  Rhynchospora baldwinii.   William Baldwin (1779-1819) was a Philadelphia physician and botanist prone to explore the Southeastern U.S. (and much beyond);  he had a jones for sedges.  His friends, enemies, and correspondents were a who’s who of American botany of the period, their names echoing through the botanical literature as specific epithets:  Amphicarpum muhlenbergii,   Eragrostis elliottii, Fraxinus darlingtonii.  Dr. Baldwin was probably mostly a swell guy, yet he dissed the work of his controversial contemporary Constantine Rafinesque acidly as “the wild effusions of a literary madman.”  The madman outlived the doctor by over 20 years.  Baldwin died of Tuberculosis on a plant-hunting excursion.

Back to Baldwin’s Eryngo.  Crush it…smell the carrots?  Eryngos are in the Carrot Family, the Apiaceae, also known as the Umbelliferae for their  trademark umbel inflorescence.  In Eryngo the umbel is squshed down to a tight flower head reminiscent of Asteraceae.

This would be a fun genus to study, or maybe a nightmare, due to the mind-boggling diversification of its species.  If Darwin had not studied finches, Eryngium could have helped illuminate the origin of species.  Around here we see Eryngium yuccifolium, Rattlesnake Master, which looks like a desert yucca, and we see and smell  the utterly different Eryngium aromaticum, which has bristly leaves not too different from some lawn weed.

Statewide there are nine species in Florida from the tip of the Panhandle to the docks of Miami, in habitats ranging from swampish to scrub,  one species endemic and endangered (Scrub Eryngium), a couple others escaped  exotics.  The garden selections are mighty pretty and are probably taken to be thistles by casual passers-by.

The crazy quilt of Eryngium diversity has not escaped the interest of contemporary taxonomists who are attacking  the genus—known for long distance dispersals, hybridizations, and rapid diversification—using DNA techniques to sort it all out.   There are over 200 species worldwide.  As varied as the species may be in overall appearances, in habitat preferences, and in behavior, they all have flowers in globose heads, and these are often blue.

Being fragrant, Eryngos collectively have big histories in human affairs.  As explained in Dan Austin’s “Florida Ethnobotany,” candied Eryngium bits were called “kissing comfits.”  They  were the breath mints of their day, except better, having aphrodisiac power.  Along these lines, and  to recycle Dr. Austin’s gleanings from Shakespeare, Falstaff said:

“Let the sky rain potatoes; let it thunder to the tune of Greensleeves; hail kissing comfits and snow eryngoes; let there come a tempest of provocation.”

Who said botany is stodgy?   In what other blog does a smelly little weed  lead to aphrodesia and tempests of provocation!

 
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Posted by on October 3, 2011 in Baldwin's Eryngo

 

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