Category Archives: Uncategorized

Three Invaders – However Did They Come?

This afternoon was hot!  John and I sweated  90 degrees to sink to our ankles in warm stink-mud near Jensen Beach, Florida to behold a zillion Bladderworts.  The site is about half overpowered with invasive exotic species and about half restored to an intriguing dried pond carpeted with carnivorous yellow Bladderworts.

Utricularia subulata 10

Bladderworts in the mud.  Photo by John Bradford.

Because we’ve covered these greedy meat eaters previously, let’s turn to the invasive exotic species.  For most of the hundreds of unwelcome escaped plants in Florida it is easy to surmise how they got here:  running away from gardens, or feeding livestock,  or hitchhiking as seeds or spores.    Some pests have have more-interesting histories.

Let’s take a shot at the novel cases, with a disclaimer that just because somebody introduced a species once does not mean nobody else did before or after.   That is impossible to pin down, and records are murky.

Sisal Agave

Sisal is a Category II invasive exotic species looming large in hot dry habitats locally.  It dates back to Florida’s first well documented horticulturist, Dr. Henry Perrine.(1797-1840).   Dr. Perrine had an eventful life, first as  “The Little Hard Riding Doctor” in Illinois, where, oops,  he accidentally drank a bottle of arsenic.   That mishap drove him to Mexico, the toxic damage causing a craving for a warm climate.  In Mexico Perrine  doctored a cholera epidemic, which he caught of course, and yet survived as his second brush with death.

Agave vivipara 1 - Copy

Sisal in Jensen Beach, by JB

In addition to doctoring,  Perrine served as U.S Consul to Mexico, coming under a presidential executive order to ship Mexican crop plants back to the U.S.   He sent them to Indian Key in the Florida Keys, and took a special interest in Agaves, including Sisal, writing a book on the plants.  Sisal was and remains a commercial source of fibers.  To this day Indian Key houses Sisal Agaves, as does much of South Florida.   Perrine retired from Mexico moved to Indian Key to tend his introduction garden, and to be a doctor where one was needed, but never lived to see the literal fruits of his labor, as he suffered “strike three,” death at the hands of angry Indigenous People in 1840, and thus ended Florida’s first botanical garden.

Water Hyacinth

Water Hyacinths are lovely floating plants with spikes of  attractive purple flowers.

All well and good if under control, but Water Hyacinth broke out and conquered Florida waters and beyond, sometimes smothering watery  acres with millions of  itself, clogging waterways and interfering with ecology.   Maybe it should become a biofuel.

Eichhornia crassipes 2 - Copy

Hyacinth to the horizon

How did a bad deed like that get started?  A careless lily pool owner?   No.  Hyacinth Hell traces back to the 1884 New Orleans Cotton Exposition (World’s Fair), where they had a mammoth greenhouse with mind-blowing horticultural exhibits.    Not bad for 1884!    But that is not exactly where the Hyacinth originated.     Each Fair visitor received one as a keepsake, only to go home all over the South and unleash the scourge.   CLICK for cinematic documentation.

Showy Rattlebox

Mirror mirror on the wall, who was the biggest plant introducer of them all?   That is easy, David Fairchild (1869-1954), namesake of Fairchild Tropical Garden in Miami.   No space here for a long biography, so suffice it to say  Fairchild had a penchant for cultivating the rich and famous, and for marrying their daughter.  He was Alexander Graham Bell’s Son in Law, and hob-nobbed with luminaries of the era, oh say Orville Wright for instance.   The opportunities and funding from his VIP connections put Fairchild and his team in a position to travel the world and introduce, via the USDA maybe 200,000 different plants into the U.S.

Crotalaria spectabilis flowers Cypress Creek - Copy

Showy Rattlebox, by JB

Included in his voluminous records are species of Crotalaria, beautiful yellow-flowered Rattleboxes, species now scattered abundantly in every disturbed site locally.    Some gardeners know Sunn Hemp (yes with double-n) as one example, although it is not commonly escaped in Florida.  A similar, gorgeous species is all over our area, well named “Showy Rattlebox.”    It is so colorful this species must have come as a garden ornamental.  Wrong.

Fairchild and his crew cultivated Showy Rattlebox and related species as companion crops for citrus and other fruit species.   Fairchild thought C. spectabilis dated to around 1920 in his Miami experimental gardens.

Crotalaria spectabilis nodules

Showy Rattlebox nitrogen fixing nodules

Beyond good looks, the species has nitrogen-fixing nodules, as a good legume should.  And willing to prosper unwatered on terrible soil in brutal sun.    Maybe that ability should have been a red flag,  but trouble took time to appear.   In the meantime, Fairchild and others waxed eloquent on the virtues of Showy Rattlebox, not only for nitrogenating fruit crop soils, but also for fighting soil parasitic nematodes attacking Papayas.

crot fairchild article


Posted by on April 21, 2017 in Uncategorized


A Mighty (Small) Oak and its bigger buddies

Quercus minima


Today John and I haunted Jonathan Dickinson State Park, near Hobe Sound Florida, finding  the flora abloom, at least in  marshy meadows,  nature’s garden complete with blooming butterworts,  orchids, meadowbeauties, milkworts, sundews, tillandsias, and too much splendor to portray with a list.

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Butterwort today.  An insectivorous plant.  All photos today by John Bradford.

The practical mission  is John’s serial  long-term photo record of “what happens after a burn.”

The blaze was about a year ago, and by now the scorched earth lies under fresh green oak boughs.   Oaks resprouted “from scratch” in a year?    Well yes, about a foot tall with no  ambition to rise higher.    These are dwarf live oak, Quercus minima, resurrecting to new life from fireproof subterranean rhizomes.

Quercus minima 2

Quercus minima towering to 9 inches tall.   The first-formed leaves are toothy lobed.

Are dwarf live oaks tiny representatives of the big  live oaks (Q. virginiana) shade trees festooned with Spanish moss across the South?    Almost.   Harvard University botany demigod Charles Sprague Sargent long ago perceptively classified both as extremes of a single species.

Quercus virginiana 8

Quercus virginiana can be huge and old.

The same question extends to a second locally abundant small oak plausibly interpretable as a variant of big Quercus virginiana.    This is sand live oak, Quercus geminata.   With variation, it is most often a shrub or smalli tree intermediate in size between big virginiana and little  minima.

What is the relationship among the three? Molecular data can settle kinship, whether for  Maury Povich or for curious botanists.    A useful DNA-centered study for today’s tree trio shows  live oak, sand live oak, and dwarf live oak together to comprise one exclusive branch on the oak evolutionary tree.  The three are most closely related to each other than any is to any other oak.    In short, it would be “legit” to see three varieties of one variable species,  or alternatively as three sister species, the latter interpretation prevailing nowadays.

Quercus germinata 3

Sand live oak

There is a compelling case for giving each its own species designation.  Chevrolet and Buick are varieties of GM yet have their own “species” identities.   Our three live oaks have diverged from a common origin over time into fairly distinct identities.    Oaks are famous for hybridizing, yet live oak, sand live oak, and dwarf live oak, all living intermixed, seem to have evolved barriers to criss-crossing, although Q. geminata and Q. minima can form a rare hybrid called Q. succulenta.     More prevalent is hybridization by each with distant cousins outside the trio.

The DNA study mentioned above is the 2015 work of botanist Jeannine Cavender-Bares and collaborators.  They noted how our  three live oaks diverge most saliently along lines of response to fire:  Q. virginiana massive, long-lived, sturdy, and intolerant of fire;  sand live oak mid-sized with grudging ability to regrow after fire; and  dwarf live oak dependent on fire.   Maybe it is all about diversification into habitats with different fire patterns.

Quercus minima hybrid

This looks like a hybrid, maybe, between dwarf live oak and Chapman’s oak.

All that said, there is an asterisk.  Quercus virginiana seedlings make a thick underground tuber before the tree grows into a mighty oak for 500 years.  Should the baby seedling be grazed, burned, or flooded it can resprout from its tuber for a second chance.   Could Quercus minima be sort of an “infantilized” live oak that remains small and took that original fireproof  temporary  “tuber” from its ancestor and expanded upon it?

Dwarf live oak has an odd foliar feature.  The earliest leaves on a branch have lobed toothy margins.  As the branch elongates, however, the younger leaves develop toothless.

Why make a transition like that?  Here is a speculation.  I think teeth and lobes on leaf margins help dissipate heat.  Maybe when the twigs are young and close to the sun-baked Florida sand below the cooling wind, where fire burned away all shade, perhaps the leaves need to shed heat.   Later, as the branches rise into the breeze, and as overhead shade increases during fire recovery, the overheating problem diminishes, making the lobed heat-shedding leaves obsolete.  Only a guess.


Posted by on April 14, 2017 in Uncategorized


Iris hexagona (or I. savannarum)

(Iris is Greek for rainbow.  Hexagona counts the angles on the seedpod.  Savannarum is where it lives.)

Iridaceae, The Iris Family

The geographical consequences of evolution do not always fit our tidy 18th Century classification categories,  iris for instance    My two favorite go-to references disagree on the species identify for the wild blue-violet iris around town.  No surprise.  Irises defy easy species classification:   they hybridize, they spread as clonal populations each with its own character,  they vary geographically.   You get the picture.  Messy.  Naming iris species is like naming clouds merging and separating across the sky.  A rich, dynamic tapestry of ever-evolving variation overmatches a classification system based on sorting dead pressed museum specimens..

Call it what you will, sometimes you just have to put a plant in the blog for its celebrity good looks.  What flower is prettier than these?  John and I stumbled upon a natural iris garden blossoming by a muddy pond near Jensen Beach, Florida.

Iris hexagona 5

The big showy droopers with yellow marks are the sepals.  Lying tightly on top of them with tips elevated are the styles.  The petals are upright between the sepals.   Photos by John Bradford.

Standby for pollination complexity. Those big showy drooping “falls” with the beckoning yellow nectar guides are the sepals, which in most other flowers are green no-count lobes upstaged by colorful petals.  The iris petals are less showy and less involved than the sepals, a case of role reversal.    Lying intimately atop the colorful sepals are the styles, likewise fancy and out of character.  In most flowers the styles are nondescript green stalks connecting the pollen-receptive stigma to the seed-making ovary. Ho hum.

Iris hexagona 1

But the iris style is a horse of a different color.   It is as colorful as the sepals, lying intimately atop them. The visiting bumblebee, the predominant pollinator in our species, pushes into the blossom squeezing between the sepal and style covering it.     The pollen-snatching stigma lies within a  hinged flap on the underside of the style, scraping pollen off of the inbound bee’s back.   Then deeper in the blue tunnel new pollen dabs onto the bee seeking its nectar reward.   As the bee backs out upon completing its mission, it pushes the stigma-covering flap closed, preventing self-pollination

Someday somebody’s going to study the hormonal life of rhizomatous clonal plants sprawling as single genetic individuals covering acres.  A single big plant with the leaves and flowers scattered across a broad network of rhizomes has a problem—how does a plant stretching all the way across a marsh communicate from one side to the other?   They do not have nerves or circulating blood.

Iris hexagona 4

The best way for the point of attack to communicate impending trouble perhaps is across the air.   Iris hexagona has attracted research attention in this connection, most prominently by biologist Susan Mopper in Louisiana.    Iris hexagona uses a hormone called jasmonic acid in conveying a danger signal probably over long distance, given that jasmonic acid volatilizes for airborne delivery.  This is extra interesting because jasmonic acid has not been a known plant hormone for very long.  And yes, it is named for jasmines where it was discovered.   Dr. Mopper and collaborators showed that saltwater stress prompted Iris hexagona to bolster its defenses against leaf-damaging insects, in other words, one “attack” spreading the alarm girding the plant for the next battle.

To linger a moment on jasmonic acid,  it seems more or less to form from damaged membranes, pretty ingenious, a warning based directly on the immediate debris of damage, sort of like pulling the fire alarm upon smelling smoke.

Ipomoea indica Baker Rd.

Morning Glory hanging around the iris, the same color.


Posted by on April 7, 2017 in Iris, Uncategorized


Leafless Beaked Ladiestresses, Dressed Up But No Visitors

Sacoila lanceolata

(Translates roughly as sac-lip, referring to the chinlike sac near the flower base.  Lanceolate leaves resemble a spear tip.)

Orchidaceae, the Orchid Family

Florida is an isolated long thingamabob jutting rudely into the almost-tropics off of the mainland U.S.    Except for raised sand ridges, scrub, South Florida was underwater until not many thousand years ago, a wink in evolution time.  Where did Florida acquire its hot-climate species? From the American Tropics in large part.  Many Florida species extend southward to South America.

Given the need to cross water to get here, you might then expect many of our species to be dispersed easily…by sea currents, by storms, by birds, by pre-European ancient seafarers.    Fern spores and orchid seeds are dust in the wind, no doubt arriving by airmail daily.

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Sacoila.    All photos today by John Bradford.

Showing up precedes the greater challenge of taking hold and spreading, which brings us to today’s orchid.    Sacoila lanceolata ranges from its origins probably in South America to a marginal outpost in Florida.  It likely had no problem arriving in the sunshine state, but multiplying and spreading presented a special hurdle.  Let me explain.

Over the last couple weeks Sacoila has flaunted its red flowers on a near-leafless stalk  in a soggy shaded swamp.  It displays those big blossoms proudly, but to whom?  Any textbook will tell you red tubular flowers that size with no fragrance are all about hummingbird pollination.  And that is a problem, because hummingbirds are  too scanty for reliable floral sex services in South Florida.  Why then is this little showoff  putting on the ritz for nobody?

The first part of a reasonable answer is easy:   it evolved elsewhere with plenty of hummingbirds, and then seeds blew to Florida and grew where it does not know its display is useless.   A little depressing, and then we wonder how without being able to complete its sexual cycle the forlorn orchid managed to spread across much of Florida.

Botanist Paul Catling looked into this question back in the 80s.    The answer split surprisingly into two answers.    First answer:  in South Florida these orchids, instead of pollination, form clonal seeds where the embryos are tiny bits of the mother plant.  No hummer help required.

Sacoila lanceolata 2

The second answer is that one population of today’s species, called variety paludicola, has a different skill, pollinating itself.

How bout that!  A species stranded in Florida without its natural pollination agents “invents”  not one but two birdless ways to make seeds.   Evolution is inventive.

Which came first, the orchid coming to Florida and then evolving pollinator-free seeds?    Or, alternatively,  did members of the species somewhere else develop one or both of the sexless seed-making mechanisms, empowering them then to invade beyond the range of their original pollinators?  I vote for the second scenario.   In fact, the self-pollinating  variety is reported from the Caribbean.

Sacoila lanceolata 5

If Florida is home to far-ranging species  colonizing apart from their usual pollination agents,  there must be additional species here with tricks similar to those of our red-flowered friend.  Plenty  Examples of local plants able to sidestep normal pollination include other orchids, pitch apple (one big female clone in FL),  daisy fleabanes,  dandelions,  Fakahatchee grass,   and agaves probably brought to FL by ancient humans.

Don’t get hung up on the word “leafless” in the name.    Leaves form, sometimes coincident with the flowers and sometimes at a separate time, and their photosynthesis feeds a hunky root system.   By the time the fancy flowers brighten the world, there’s been a lot of  root-building off-stage.     The plants probably go years without flowering at all.



Posted by on March 31, 2017 in Sacoila, Uncategorized


Why John buys duck stamps and why you should too

You may hope that the Florida legislature provides the funds to buy land for water storage but I know that when I buy a duck stamp the 98 cents of every dollar is mandated to buy wetlands.

Duck stamps are the greatest federal program in existence. 98 cents out of every dollar goes to buy wetlands. That is a Federal mandate. Since 1934, when the program began, it has purchased or leased over 6 million acres of wetland – an area nearly the size of Maryland. Much of this area is now part of the National Wildlife Refuge system. It’s the envy of the world.

Stamps have enabled the purchase of over 2500 acres at the Arthur Marshall refuge and almost 86,000 acres in 6 other refuges in Florida.

And here is the backstory:

In 1934, our country suffered in severe economic depression. Real needs were many; financial resources were slim to non-existent.  At the same time, our abundant natural resources were rapidly disappearing. In an era when hunting still provided the meat on many tables, it seemed there were more hunters than ducks.

As chief of the U.S. Biological Survey, forerunner of today’s U.S. Fish and Wildlife Service, J. N. “Ding” Darling devised a program wherein hunters became stewards of the wildlife they hunted.

“Ding” Darling was most widely known for his editorial cartoons, which appeared in nearly 150 newspapers nationwide and earned him two Pulitzer Prizes.

Although “Ding” earned his living as an editorial cartoonist, his passion was teaching the wise use of the world’s natural resources. Skilled in public speaking, articulate in writing, Darling devoted his special talents to conservation education and to developing programs and institutions which would benefit wildlife.


One of “Ding’s” cartoons

Darling’s Design for the First Federal Duck Stamp~1934 is especially significant to conservation. After he had guided the funding for the Migratory Bird Hunting Stamp Act through Congress, Darling sketched his concept of a suitable image for the First Federal Duck Stamp. With its enthusiastic adoption, a remarkable program of stewardship was born that endures today, more than a half-century later. Here is an image of “Ding” Darlings original stamp:



Not only does the stamp provide the funds to buy and maintain the wetlands it provides a beautiful piece of artwork. Every fall hundreds of painters across the country compete in the Federal Duck Stamp contest, which gives participants a chance to have their paintings featured on the duck stamp of the year. So when you buy the stamp not only are you saving wetlands but you are buying a wonderful piece of art. Here is an image of the current stamp depicting Trumpeter Swans

2016-2017 Federal Duck Stamp

If you want a great read about the peculiar world of competitive duck painting then pick up a copy of The Wild Chase by Martin J. Smith. This book follows the Federal Duck stamp contest of 2010. If you saw and liked the movie “Best In Show” you will really enjoy this book. Some of the descriptions of the ducks and geese in the 2010 duck stamp contest were hilarious. The Brant, a smallish goose is like a feathered Martha Stuart – they put more down in their nests (for insulation) than any other waterfowl. The Northern Shoveler is Lady Gaga of the wetlands – iridescent green head and neck and really showy plumage. The Ruddy duck is an oddball – a skyblue bill that is just ridiculous. The Ruddy Duck appeared on the stamp in 2016

Ruddy Duck

Another interesting duck is the Red-breasted Merganser who looks like he had his hair styled by Woody Woodpecker.  The bird appeared on the 1994 stamp.



I hope you will consider the purchase of a stamp as part of your conservation effort. Here is a link to the Federal website that contains a lot of duck stamp information:


I buy my stamps from the US Post Office and here is that link:


Posted by on March 24, 2017 in Uncategorized


Persimmon’ll Tan Your Tonsils

Diospyros virginiana

(Dios, god,  pyros, grain = divine grain, an ancient name for a tasty treat.  Virginiana is self-explanatory, a great state for Persimmons and for lovers)

Ebenaceae, the Ebony Family

Fridays!  Deployed for non-teaching:  on a bad day meetings, on a good day botany.  Today, eye doctor, delaying the fieldtrip with John until late in the day, when we found stunning red-flowered Leafless Ladies Tresses, Sacoila lanceolata.   I was too doctor-blind to shoot a picture, and John needs time to process his.  Will sneak it into a future blog cuz it is so dang purty.  So then, in 20-20 hindsight, my Native Plants Class yesterday encountered more beautiful species at Grassy Waters Preserve near Palm Beach Gardens, Florida, than you can shake a Sacoila at.

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Persimmon. All photos by John Bradford.

Blooming now in the wet mud there is Persimmon,  a tree I know best from rocky hilltops in The Ozarks, and more recently as a wet friend in the swamp.    The contradictory divided habitats seem odd?  Species represented in swamps and also high and dry are not that rare, but that’s for another day.  Persimmon tolerates diverse circumstances across much of eastern North America.

Persimmons have hundreds of species, a few to be seen or eaten in Florida, although D. virginiana is the only native. Diospyros kaki, an Asian species with many cultivated selections, is the big orange persimmon of grocery stores.   Florida fruit fanciers likewise savor “Chocolate Pudding Tree” (Diospyros digyna, aka D. nigra,  aka Black Sapote).   Escaped at the southern tip of the state is the Malay Persimmon, D. maritima.   True Ebony, Diospyros ebenum, is cultivated a teensie weensie here in Palm Beach County.

Multiple species of Diospyros are marketed as “Ebonies,” which raises the question, does our native species have dark “ebonyish” heartwood? Yes, and there’s more.   The chunky bark served historically as a source of inky dark dye, and “indelible ink” reportedly can be made from the fruit juice.

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Peach colored petioles.

In the absence of bark, fruit, or flower, Persimmon can be challenging to recognize, but here is a handy hint…the twigs have no buds at their tips…they just fizzle out.   Good clue, and here’s more, the leaf stalk tends to be reddish or peach colored, at least when young.

Native Persimmon is one of the most delicious foods in the megaverse.   I’d trade a bushel of Chocolate Pudding fruits and Publix Persimmons for a half-dozen fresh ripe native Persimmons, but good luck finding any here.    Scarce they are, and the wildlife beats you out.   To be totally tasty, they need a frost, although there are frostless cultivated selections.  The trees are separately male or female, and they clone by root suckers, with the consequence that an entire “population” can be completely male, never making fruits.

Biting an unripe Persimmon fruit is memorable.  Pucker up Buttercup!    It is astringent on steroids, which explains the old-time use of the juice to relieve “piles.”    Astringents still help down south, and it all has to do with tannins.    Tannins are plant products with a super-power—to bind proteins.    That is how tannins tan hides…they tie the proteins to each other, helping to preserve the skin  presumably by rendering the proteins inaccessible to decomposers.  (This to be more my presumption than scientific fact.)   In your mouth, they “tan your hide” too, instantly interlinking the proteins there.   That is potent protection from unwelcome nibblers.    DO NOT even think about eating my fruit before it ripens! (The seeds are not yet good to go.)

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The flower, magnified

But how then does the fruit go from dreadful to delightful upon ripening? Early in development the tannins collect in special cells called, yep, tannin cells.  Little bags of trouble.   The toxic tannins sequester safely until they cross your lips.   You might think chewing breaks the nasty little bags to unleash the torment, but wrong.  Back in 1906 botanists showed the tannin trigger to be saliva entering tannin cells by osmosis.   No need for a biology lesson on osmosis here; suffice it to say dissolved tannins draw spit into the tannin cells to build pressure and burst the little poison balloons.

That explains the punishing pucker.  But we ask again impatiently, how do the fruits become harmless abruptly when the time is right?   Does the tannin go away?  No.   The tannins condense into harmless crunchy grains no longer having the ability to draw in water nor to bind proteins.  Has Persimmon served to tan leather?  Yes, although commercially there are better sources.


Posted by on March 17, 2017 in Persimmon, Uncategorized



Thank you to everyone who registered, and apologies to anyone who tried to sign up but found the class filled.   Happened fast.    Given the volume of the response, we’ll probably offer it again after this.


Posted by on March 14, 2017 in Uncategorized

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