Buttonweed (Shrubby Flase Buttonweed) (and the wasp and the cricket)

Spermacoce verticillata

(Spermacoce means seed-point, because the little dry fruits have four points.  Verticillata presumably refers to whorls (verticils) of  flowers and young leaves.)

Rubiaceae (Coffee Family)

Common plants interest me more than the rare species, because the common ones are everyday friends.   There’s so much to discover right under our noses.   Today’s plant is literally everyday in parking lots, asphalt cracks, roadside weeds, pastures, and lawns.     Spermacoce verticillata is an exotic invader from the Coffee Family as well as one of the most abundant and toughest weeds in South Florida.   If you live here and want to see it,  step out the door.  The plants can rise five feet tall, or lie low and spread into a patch where grazed or mowed.    On top of overall immortality, the plants re-root where they touch the ground, and the tiny seedlike fruit segments boast a 50 percent germination rate.  There’s no stopping it.

Buttonweed on dismal soil.  It doesn’t care.  Today’s photos by John Bradford.

That is good news is you dislike mole crickets.    The holy grail of pest control is a natural approach using pests of the pests, although that has been known to backfire when the attackers spread to native relatives of the target enemies.

Evil pests of Florida lawn-lovers are invasive mole crickets, multiple species.    Their arch enemy is a parasitoid wasp Larra bicolor, introduced from South America, as is today’s weed, the wasp’s favorite nectar plant.    The wasp lays an egg on the mole cricket, where the resulting larva sucks life from its host, terminally.  All  natural cricket control!    Buttonweed is available commercially to foster the cricket-killing wasps.  In that context call it “Larra Flower” echoing the Latin name of the wasp, although somehow I don’t think market-driven neo-naming will stick any better than “Freedom Fries.”

Here we have a case of cultivating one invasive exotic to feed another introduced exotic to encourage it to kill still another invader, an exotic ménage à trois.   All three species have native Florida relatives.  I have scant idea if that implies risk.  From a standpoint of general principles, ignorance, and neurotic personality, it worries me a little, especially  with respect to native mole crickets, although studies do show them to resist the wasp, so that risk is probably, if not certainly, low.   Spermacoce verticillata is so ubiquitous already that cultivating more is not likely to cause additional harm.

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Relevant link for extra info

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Sea-Purslane and the Sucky Salt

Sesuvium portulacastrum

(Sesuvium references an ancient Gallic tribe.   Portulacastrum notes false similarity to Portulaca.)

Aizoaceae

 

A  romantic stroll on the beach in Florida or throughout much of the warm climate world may reveal a trailing succulent with showy purple-violet flowers. The fruit opens like the lid of a Weber Kettle to allow seeds to splash out, much like the pod of its namesake Portulaca.

Sea-Purslane sometimes goes by the name Sea-Pickle.  Plant munchers eat the salty succulent leaves.  Perhaps not a grand idea, however, as the tissues are powerful mercury (and probably lead) accumulators, not to mention producers of steroid hormones.   A few words on those:

Twenty-hydroxyecdysone is a steroid touted for boosting testosterone for virile body builders. I think the claim is spurious, and who wants to go around ingesting hormones?  If John and I become more manly we’ll be dangerous.

Photo by John Bradford.

Why would a plant make animal-active steroids?  Twenty-hydroxyecdysone is an insect molting hormone, serving to disrupt insect development, thus perhaps a future natural insecticide crop.

Insect damage to Sea-Purslane was the object of a hurricane recovery study in the Bahamas where hungry moth larvae undaunted by hormones stifled hurricane recovery by eating the pickles faster than they regrew.    What saved the day was a population of Brown Anole lizards, native in the Bahamas and introduced and established abundantly in Florida.  They had the fever for the flavor of a caterpillar.

It is always curious how plants of salty places cope with all the salt.   Some secrete it one way or another.   But Sea Purslane stores it!  Exposure to salt, in fact, up-regulates hundreds of known genes and enhances growth. The plants sequester extreme salt concentrations within the thick leaves, in the vacuoles to be exact.  A vacuole is sort of a bag inside a plant cell, and stashing the salt there may cut down its damage to basic cell functions.

The “purpose” of the stash however is not to place the salt out of harm’s way, but rather it seems using it in a “fight fire with fire” strategy.   The beach sand is highly salty of course, and that draws water out of the roots by osmosis.   You might say “salt sucks.”  People have long known that salt in the soil kills plants.   To smite the Sichemites, sow salt on their fields and dehydrate the crops.

Sea-Purslane fights salt with salt.   If a high soil salt concentration forces a tug-o-war for water, the way to win is to have even more sucky salt in the leaves.    A thick stand of Sea-Purslane can take up enough salt to diminish meaningfully the salt concentrations in the soil,  an observation not overlooked in soil reclamation.

 

Down and Dirty

Bulbs, Corms, Stolons, Tubers, Turions, and Bulblets

(Some of today’s images are from our earlier blogs in different contexts.)

Today’s topic is the suggestion of Pasco County Biologist Katie MacMillen.   As John and I explore the hottest, driest, wettest, most disturbed, and most fire-prone habitats, we see a recurrent theme, as Katie noted:  all manner of subterranean contrivances to allow plants to recover after trouble above…be it fire,  sun,  frost,  flood, or fauna.    We explored Halpatioke Park today for insects in a low area sometimes submerged sometimes dry.    A perfect rhizome zone!

Patience please!  A quick vocabulary lesson:

A rhizome is a horizontal stem usually beneath the ground level.    Tasty example, ginger “root.”

Torpedo Grass rhizome

A stolon is thin rhizome running across the ground surface.  Familiar example, runners connecting grass clumps.

A tuber is a thick fleshy rhizome or an expanded rhizome tip.   For instance, potato, or caladium “bulbs.”

A corm is a short thick vertical stem just below ground level.  Garden example:  Gladiolus “bulb.”

A bulb is a thin vertical stem surrounded by layers of thick fleshy leaf bases. Routine example: onions.

The common names for these structures are messed up and confusing.

In the local native flora we have it all:

The hunkiest local rhizomes might be those of Spadderdock, Nuphar,  several inches in diameter and several feet long.  In addition to surviving dry times, the big rhizome has an astounding second function.  Spadderdock  has pressurized airflow with some leaves taking in air and forcing it downward through the leaf stalk and then through the rhizome,  eventually back out through other leaves.

Somebody is sitting on the Spadderdock air intake

 

Spadderdock rhizome

 

Also well endowed rhizome-wise, Smilax  may have more biomass below ground than above.     It can pop up vigorously after a fire, often climbing the charred remains of its former competitors.

Smilax tuber. By John Bradford.

The aquatic emergent Sagittaria has textbook tubers, sometimes called “duck potatoes.”  And they are tasty like a tater.    So are the nuts (tubers) from the exotic weed, Yellow Nutgrass.    Those who cook it call it Chufa.

Weeds are adapted to existential threats.  Survival can be via tubers…ha ha you can’t yank, burn, or graze me…because I’ll rise from the ashes.  The comely lumpy white tubers of Florida Betony (Stachys floridana) give the plant the name Rattlesnake Weed.

One of the worst weeds ever is Tuberous Sword Fern, combining the ferocious dispersal power of wind-blown spores with the immortality of tubers.  Who said, “you can’t predict which introduced species might escape and become weeds”?

Some plants use tubers not just to persist, but also to spread, especially easy in aquatics such as the invasive pest Hydrilla, which in addition to float-away tubers has secondary smaller tuber-like units, called turions.

An odd tuber(ish) structure forms while a Live Oak is a mere baby, in its youth susceptible to ground-level hazards before achieving mighty oakdom.

Tuber on Live Oak youngster. By John Bradford.

Corms happen here too.   For instance,  Blazing Stars,  Liatris species survive the trevails of exposed life via the dark underbelly of corms.    If you buy garden Liatris you are most likely to buy corms marketed as “bulbs.” Likewise cormish is the Aroid Family, for example, Jack in the Pulpit and Arrow-Arum in Halpatioke Park today.

Liatris corm by John Bradford.

And then come bulbs, especially in the Lily Family and relatives:  Catesby’s Lily and Spider-Lilies are all native local bulb makers.   Our Halpatioke site today had bulb-bearing Crinum Lilies all abloom this morning mixed with rhizome-rich Cannas.

The introduced pink woodsorrel makes tiny bulb(let)s near the root-stem interface and elsewhere.   The species makes no fertile seeds, the bulblets seem its sole means of reproduction and dispersal.

Why is all this underground business based on stems?  Isn’t the dirt the domain of roots?  Sort of.  There are plants with creeping roots and thick storage roots, such as sweet potato, or its big-rooted native relative Largeroot Morning Glory.   But stems have a more versatile, more diversified, more flexible structure than roots, so when evolution messes with a plant’s structure for a novel purpose, “stem” appears to be a better starting point than “root.”

Why do so many wetland species have so many rhizomes and tubers?  Aren’t they safe in their nice moist marsh?   For starters, where we encounter a species is not necessarily reflective of where it evolved.    After all, most of Florida was under salty seas a few thousand years ago, so our marshy  friends mostly evolved elsewhere before settling into Florida.

Secondly, a lot of shallow-water plants face intermittent drying.   Pine flatwoods are full of summer ponds-winter meadows.  Many evolved on shores or littoral shallows with fluctuating flooding, drying, and disturbance.  Also, excessively deep water could be a foliage killer.

Yet another advantage of underground rhizomes for aquatics is a relentless war for space.   When you look at an open shallow body of water there are immense single-species clonal clumps covering acres pushing and shoving with other massive clumps.  Reminds me of 2017 politics, including the subterranean aspects.  Victory requires spreading aggressively by rhizomatous growth, by rhizome fragmentation, and by territorial turions.  Go forth and multiply.   Seeds are good, but rhizomes are better at pushin’ and shovin’.

Two armies at war.

 

 

Do Flowers of a Feather Flock Together?

Old World Diamond Flower (Oldenlandia corymbosa) Rubiaceae (Coffee Family)

Rustweed (Polypremum procumbens) Tetrachondraceae

 

John and trekked out to where the wild things grow today, only to retreat beat by the heat.   (Not John, I was the wimp.)  But not before a familiar observation:   clustering of similar yet unrelated flowers in a specific habitat.  A hunch rooted only shallowly in the botanical literature, so we’re in the realm of suspicion, not fact.  Maybe that heat got to my head.

Ever visit a natural place and perceive many unrelated flowers to look alike, especially in coloration?     A wet meadow may feature bright yellow xyris, bright yellow St. Johnsworts, bright yellow coreopsis, bright yellow heleniums, bright yellow smallfruit beggarsticks, bright yellow ludwigias, and more, although not to the exclusion of other colors.   Large white giant whitetops and large white alligator-lily grow together.  Where does imagination end and correlation begin?

Color clustering might be conceivable if you look at it this way:  pollination is essential for existence, so a plant is going to exist only where its proper pollinators are.   Different types of pollinators have different frequencies in different habitats, influencing the plant species composition, and thus perhaps trends in flower color and size.

Furthermore, and only a notion, maybe there is positive feedback, say, for example, a happy place for bumblebees brings bumble-visited flowers, which then draw more bumblebees, and these in turn support more bumblebee-o-centric flowers.   Bees like yellow.

This morning’s site, Haney Creek Natural Area in Jensen Beach, Florida, has a dry, sun-cooked, sterile, disturbed gravel road with a preponderance of very small white flowers.  “The same” road with essentially the same species runs behind my home, where almost all the flowers were about ¼ inch or less in diameter and white.   All of the photos today are taken in one small flower patch at the same magnification except for the over-magnified Buttonweed whose flowers are essentially the same size as the others.  Maybe that harsh habitat fosters tough little bees or mini-flies adapted to tiny white blossoms.

That harsh environment is probably not a place for plant species with big, showy, “expensive” flowers to support large insects demanding abundant rewards in nectar or pollen.    Skimpy man habitat, skimpy flowers, skimpy pollinators, perhaps.

Floral resemblance among the species growing intermixed there can be striking.  Below are photos of two unrelated plants:  native Rustweed (Polypremum procumbens) and non-native Old World Diamond Flower (Oldenlandia corymbosa).    Their flowers are “stamped from the same mold.”

Rustweed

Old World Diamond Flower

Non-native Buttonweed was growing among the others, and has much the same look.   This photo is at much higher magnification than the rest.

As an aside, Rustweed goes through a remarkable seasonal color change.    It starts out green and as the summer progresses switches to a coppery rusty color.

Rustweed in the rusty phase.

The other species consorting with the Rustweed and Diamondflower looked much the same too.   What makes the similarities even weirder is that the “flowers” are not all true flowers.  In the Canadian Horseweed they are a collection of smaller flowers collected into a white flower-head.   In the Sandmat and in the Euphorbia, the “petals” are itsy white leaves surrounding smaller flowers.  Yet they all have converged on the same general appearance, perhaps to accommodate the same floral visitors.

Boerhavia erecta, mixed with the others.  Not native.

Grassleaf Euphorbia, hanging with the others.   Not technically a flower,  but posing like one.   It is a cluster of small flowers associated with those small petal-like leaves. The big green lump is a fruit.

Sandmat, another non-flower disguised as a small white flower,  constructed similarly and related to the euphorbia immediately above.

And another in the “little white flower” patch. Canadian Horseweed.  The “flower” is a flower head made of many.

There must be something good about that “little white flower” look, because everyone on the berm is doing it.   And that good thing is probably shared pollinators.    Just a hunch.

 

Tassel Flowers, Twin Species with Twin Hairs

Emilia fosbergii (usually red, with variations) and Emilia sonchifolia (lilac)

(Emilia is a personal name, but the identity of Emilie or Emile is lost history.  Raymond Fosberg was an American botanist.  Sonchifolia means “leaves like Sonchus,” a related genus.)

Asteraceae

 

Twins!  One with red flowers, the other with lilac.   Every person within the ranges of these two beauty weeds has noticed their bright flowerheads somewhere.    Venus’s paintbrushes.  Native to the Old world,  they grow from the boondocks to Wal-Mart parking lots, often together.    Can’t miss em’.

Emilia fosbergii, flowers usually red.  By John Bradford.

Emilia sonchifolia, typically lilac.  By John Bradford.

Being so similar, ultra-closely related, and often mixed, I wondered if the two might form hybrids, especially because flower-color intermediates exist.   The tweeners look like obvious hybrids.   But watch out, “obvious” conclusions send innocent convicts to the chair.

There is hybridization afoot, but not what we were thinking.  It happened long ago:   Emilia fosbergii is  the result of an ancient cross between Emilia sonchifolia and another species.    Botanists who study these plants suspect the “other” species to be the red-flowered Emilia coccinea which occurs in the U.S. only as a garden flower.    So did you catch that, E. sonchifolia is a “parent” of E. fosbergii.

The hybrid origins of Emilia fosbergii help explain the color intermediates in a new refreshing light.   One parent species, E. coccinea has bright red to orange flowers, the other parent, E. sonchifolia has lilac blossoms.  Our hybrid species E. fosbergii usually (in Florida at least) tends to be red, and varies to pink or light violet.  In short, it can resemble variably either or its parent species.   It has a full set of chromosomes from each, thus the genetic blueprints for each.

Twin hairs on the “seed.”

The Emilia fruits resemble dandelion “seeds” suspended from a parachute.   The tiny seedy paratrooper (technically an achene) has an unusual feature, twin hairs, side-by-side hotdog-shaped outgrowths.    Recent studies reveal paired functions for the paired hairs.  The first function is to serve as intake ports for water entry as the seed contacts wet soil.   Little “roots.”  The second function is a bit root-ish too:

To release mucilage…remember mucilage glue?…to fix the seed to the soil particles.  It still has a parachute attached and may otherwise blow around, disrupting germination and establishment.

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E. fosbergii, so pretty. By John Bradford.

*To rephrase more precisely for those who care:  Emilia fosbergii appears to be an allotetraploid potentially of African origin with one subgenome from diploid E. sonchifolia (well substantiated) and the other subgenome (speculatively) from a diploid biotype of E. coccinea which has diploid and tetraploid biotypes.

 

Alligator-Lily, Palmer’s Spider-Lily

Hymenocallis palmeri

Amaryllidaceae

(Hymenocallis means beautiful membrane in reference to the white funnel at the flower center.   Edward Palmer was a Civil War doctor-turned botanist who discovered today’s species in 1874 at Miami.)

Etching of Hymenocallis palmeri from 1888. This is probably based on Edward Palmer’s collection.

Some species are born to be stars with celebrity good looks.  Alligator-lily is one.  Circumstances prevent a Friday field trip, so the replacement is a wet meadow down the road from my house, a rainbowland of violet meadowbeauties, white painted sedges, shocking pink Bartram’s rose-gentians, yellow xyris,  and much more, including alligator-lilies, so showy and so odd.   The spider-lily genus Hymenocallis is native to the Americas, and in gardens worldwide.  Several species occur naturally in Florida.

Hymenocallis latifolia, by John Bradford

Alligator-lilies beautify most of south Florida plus a satellite outpost a little to the north, preferring wet habitats, usually sunny, such as wet prairies or soggy meadows.   Sunny and wet will matter again in a moment, so hold the thought.

Alligator-lily

The flowers are huge, white, fragrant,  nectar-filled,  and fancy in silhouette.   Vaguely funnel-shaped, they have a narrow tube as long as your hand.     In other words, textbook moth-pollinated, almost exclusive to hawk moths sporting proboscises like flexible knitting needles uncoiling to probe the tube.

Pollinate here:  CLICK

All that is well documented on the internet, so with that low-hanging fruit plucked we shall plod  onward to  the actual low-hanging fruits.  As low as snake spit.  Spider-lilies have a fruit-seed system rare in the green world.   The fruits start out normally as pods atop the flower stalk.    As the seedpod enlarges and gains weight the stalk flops to the ground like that aforementioned snake.

Green snakes

The flimsy pivot point is at the stalk base, and the seedpod is the snake’s head.

The grounded pod splits open and reveals the enlarging succulent green seeds.   The embryo is a mere undeveloped speck at this point.   And here begins the seed weirdness Louisiana botanists Muriel Whitehead and Clair Brown studied painstakingly in the 1940s using a different Hymenocallis species.

The seeds look like green grapes.

Instead of forming hard dry seed coats and going dormant like a proper seed, the spider-lily seeds behave more like independent plants.  They simply remain green and grow on their own before germination.   They photosynthesize on the ground apart from the mother plant,  feeding that little nub of an embryo  until it gets big and sprouts forth in about a month.   The thick green soft living seed coats have a unique system of  veins, resembling those in a leaf, adequate for the job of distributing the products of photosynthesis.   They even have stomates, which are the microscopic  gas exchange valves typical of photosynthesizing leaves, not normally on seeds.

Seed cut open like a quartered melon.  The immature embryo top left.  The seed coat is soft, succulent, green, and photosynthetic.

To summarize,  most plants pack their seeds pre-release with a developed embryo, nutrition for it, and hard layers of protection to go dormant and then reawaken in the right place at the right time under the right conditions.    This plant, by contrast, drops an independent living soft green seed onto the moist mud to handle its own nutrient production to bring an unformed embryo to mature germination.

And now pesky ones may say, “well you covered the base of feeding the embryo, but what about protecting it?  These seeds have no seedcoats to block pests.”    True,  but these are wickedly toxic  plants.    The seeds in the photo above are glossy green and unbothered.

Unauthorized personnel.   Is the grasshopper (Aptenopedes sphenarioides probably):  rendering itself poisonous borrowing toxins from the plant?  And/or eating the petals as the least toxic parts?

 

 

 

Hempvines

Mikania scandens, and related species

(Josef Mikan was a botanist in Prague.  Scandens means climbing.)

Asteraceae (The Aster Family)

 

What did Charles Darwin do after rocking the world with evolution?    The aftermath was a little anticlimactic, like a retired CEO heading the homeowners association.    One thing Darwin did was study climbing vines, and one of his climbers was Mikania scandens.   He queried through international correspondence if Mikania scandens always twines in the same direction as it climbs.  Darwin sent letters on sailing ships.    I used Google Images, and every Mikania I see there cranks counter-clockwise.   (Would they go clockwise below the equator? (Just kidding.) ((I think.))

Mikania scandens wrapping counter-clockwise.  By John Bradford.

John and I rocked the world today working on insects and frogs in Savannas State Park near Jensen Beach, FL, a perfect place to trip over Mikania scandens.

Florida has three species of Mikania:   Mikania scandens, the similar M. cordata, and the reason I’m mentioning the trio:  The exotic invasive Mikania micrantha is called Mile-a-Minute Vine growing 60 MPH and blanketing acres in the wink of an eye.   Good thing it is, I hope, sprawling only across the Miami-Dade Area.   But all things do have their good points, and a smothering rampant vine is just what you need if you have something to hide   Camouflage is how it served during WWII, the military helping to spread it around the tropical world.   War has odd ramifications, such as that (dud) hand grenade a bicyclist stumbled upon, almost literally, recently trailside in Jonathan Dickinson State Park, aka WWII Camp Murphy.

Mikania cordifolia in fruit. By JB

Our bio-peek today is about hand grenades, tiny ones, if the story that follows bears scrutiny.   Please know that the tale resembles the prosecutor’s case…made-up to account for the facts as we know them.  Innocents have gone to the chair on occasion.

First a little background.   In the Aster Family, where Mikania belongs, the flowers are crowded into dense clusters called heads.   The flower bases are packed together side-by-side vertically like stems in a vase.    Each base matures into a fruit similar to a seed, so let’s just wink and call it a seed (if you prefer, call it an achene).    Packed with sugars and starch, seeds are good to eat.

Diagram of an Aster Family flower head.  The flower bases (ovaries in the caption, blue) are packed together vertically and become the “seeds.”   In real life they are jammed together, not separated as in the diagram.

Seed pests are a pervasive torment for members of the Aster Family.  Little troublemakers, often tiny maggots, nestle down among the maturing “seeds” and damage them by nibbling.

Maggot enjoying the “seeds” in a related species, Bidens alba.   The plant needs defense.

The crowd calls out DE-FENSE, DE-FENSE.   Here come those micro hand grenades…packed in among the seeds.    Under a microscope little hard grainy translucent spheres cover the seeds.  The little death bombs (if my speculative interpretion of their purpose is correct) are a handbook recognition feature for Mikania scandens.  (M. micrantha can have some as well.)

“Seed” (achene) removed from the flower head covered with what I think are anti-maggot death bombs.  The white material to the lower right is a parachute…think of a dandelion for familiar related species with parachute seeds.

A loathsome larva has to nibble and wriggle past the tiny spheres to get to the tasty seedflesh.  They break loose easily and perhaps even stick to the pest infusing it transdermally with toxins like “the patch.”

Defensive weapons need some zip, and our species has plenty to give although I don’t really know if the seed-covering gems contain the secret sauce.   That sauce is beyond toxic.  Its diverse ingredients include a wicked compound named for the plant, mikanolide.  It (and maybe its associates) block the enzyme DNA polymerase.  That may sound harmless without a reminder of its necessity in forming DNA, the genes, the info center for every living cell.   Nuking the DNA would be the same as yanking the motherboard from my laptop on my lap.   Poisons don’t get much more direct or universal than that.

So clearly Mikania has the right stuff  to destroy ANY living cell,  whether it be a seed-munching larva or a malignant human tumor.   (Please do not eat the weeds.)  Tilted more toward that tumor,  mikanolide-based therapy has made it to the U.S. Patent Office.