Myrsine cubana and the junky trunk

(Myrsine is an ancient Greek name for a shrub, and may trace back to myrrh.  Cubana refers to Cuba.)


(Readers will find this plant under divergent species and family names.  It has a messy history.  Here we follow the Flora of North America.)


John and I wandered dodging cacti over sunny hill and sandy dune in the scenic Jupiter Lighthouse Inlet Lighthouse Outstanding Natural Area today, formerly a Coast Guard LORAN navigation station by Tequesta, Florida.

Our local Sahara Desert scrub is always a living museum, at least when not 94 degrees, and likewise interesting is the interface where scrub meets mangrove seashore.    Such borders are often home to a mixed bag of species.   Today there in bloom was Myrsine, a shrub popular among native landscapers decoratively and as birdfood.  Our species is just one of approximately 300 species of Myrsine.    In Florida Myrsine cubana favors near-mangrove areas and coastal hammocks.

The flowers are mostly unisexual, and many folks describe the species as dioecious (dye-EE-shus), that is, with separate male and female individuals, although the truth is more complex.  The authoritative Flora of North America avoids tagging it as that.

Rapanea punctata 3

Myrsine stems with flowers, by John Bradford.

The little cream-colored flowers sit crowded along older woody branches, partly hidden among the leaves.    Somewhere along the line my students started describing it as having its “junk on the trunk” (hey, don’t look at me), although I don’t think the trunk itself has flowers.

Myrsine flowers

Myrsine flowers today.

The term for bearing flowers and fruits along older branches or on the trunk is cauliflory.  Familiar examples include chocolate, jaboticaba, and mastic, or for northerners, redbud.   Cauliflory turns up sporadically among the flowering plants, having evolved independently in many different families.   Why?

There is probably no single reason, although botanists seem to find the condition mostly tropical, and probably with at least three benefits in addition to  strurdiness:  1)  In a tropical forest having a multitiered canopy many insect pollinators live “down low,” not out at the tips of the ultimate branches.    2.  In a tropical forest, not all potential pollinators fly.  Stem-borne flowers invite pollen dispersal from crawling insects, lizards, small mammals, mangrove crabs, and treefrogs.  3.  Birds don’t always fly; they also sidestep along branches.  That could help distribute pollen, and more importantly, perching birds as well as rodents can feast on the thousands of small black berrylike Myrsine fruits and help disperse the seeds.

Rapanea punctata 1

Junk on the trunk, by JB.


Posted by on November 17, 2017 in Myrsine, Uncategorized


Strap Fern Sitting Pretty

Campyloneurum phyllitidis and other epiphytic ferns

(Campyloneurum references curved veins, and phyllitidis refers to an ancient name for a fern.)


Today’s botanico-adventures were in the Cypress Creek Natural Area near Jupiter, Florida, working on John’s photo guide to the natural areas.     There are small, old, concrete culverts and water control structures, long neglected and overgrown, now shaded hideaways for mosses and ferns. An exceptionally attractive fern perching on a mossy old dam is Strap Fern.

Campyloneurum phyllitidis 5

Strap Fern on a tree.  All photos today by John Bradford.

Of course the fern did not evolve with decaying concrete to colonize, and its true calling is as an epiphyte on branches, rotting stumps, and most compellingly perched on cypress knees.

Cypress knee with strap fern 2

On a cypress knee.

Florida epiphytic (living up on other plants) ferns are prime examples of diversified adaptations to meet the same goal…survival with no roots in the soil.   Most of the epiphytic ferns here have some oddball features to thrive high and dry.

Most famously, Resurrection Fern, in addition to tough leathery leaves and water-retentive scales, has the supernatural ability to go into suspended animation when dry, and then to “resurrect” on a rainy day like today.

Pleopeltis polypodioides 13

Resurrection Fern.

Most weird-lookingly, Shoestring Fern dangles from tree trunks, usually Cabbage Palms,  as narrow strands like hair hanging from a head.   I think its main protection from drying is having its stomates (pores where water departs from leaves) hidden in a groove under a curled leaf margin.    With its stomates thus blocked, the fern retains its water, but then can’t cool evaporatively, which may be why the leaves are skinny “shoelaces” with huge collective surface area cooled in the breeze.  Air cooled not water cooled.  Less conspicuously, the fern roots penetrate the decaying tree “bark” and associated tissues aggressively, using the soft wet outer tree trunk as a substitute “soil.”

Vittaria lineata 2

Shoestring Fern.

Most robustly, Golden Polypody Fern sends long thick rhizomes wrapping all over its host (usually Cabbage Palm) trunk.   It seems to make up for not having a root system in the ground by making a large “root system” up on its host.  Who needs soil when you can probe the moist earthy world of old palm leaf bases?

Phlebodium aureum 1

Golden Polypody

Today’s fern has its own peculiar adjustment to epiphytic life.    We need a little history to understand.   DNA study shows Strap Fern’s ancestry to be more-typical looking ferns with divided “ferny” leaves, whereas Strap Fern evolved undivided leaves, just long  entire-edged straps, usually fairly erect.

Here is where we depart from specifics on Strap Fern and expand to broad generalities seemingly applicable to the present case.

Botanists think that ferns with funnel-shaped clusters of undivided leaves have evolved to funnel water and nutrients caught from the rain and leafdrip.   A fern rooted in the soil can get water and nutrients it needs from the earth.  Its biggest problem might be distributing enough light through its leaf system, which might explain why most shade-dwelling  terrestrial ferns have frilly divided leaves…to let the light through to lower leaves.

But an epiphytic fern, by contrast, has lifted itself up into a brighter habitat where light is comparatively adequate, but needs to capture all its water and nutrients from above and direct them to its small and superficial roots.   The leaves evolve consequently from lacey to strappy.   Beyond ferns, many flowering epiphytes have that funnel shape:   some anthuriums, bromeliads, and orchids for example.

Campyloneurum phyllitidis 6


Posted by on November 10, 2017 in Strap Fern, Uncategorized


Cypress as Old as the Tower of London

Rare treat today.  John, Dee Staley, and I joined the Friday tour of Barley Barber Swamp near Indiantown, Florida, led by Treasured Lands Foundation Director Chuck Barrowclough.   So much to see and learn there, from an ultra-modern solar-gas power plant to an ultra-ancient Seminole fish-catching canal.

Taxodium distichum 2

Cypress cones, by John Bradford.

Anyone can register for a tour through the Foundation’s web site, then don’t skip the best lunch in town at the historic Seminole Inn in Indiantown, former equestrian home of Davy Jones of the Monkees.

The swamp has unique attributes:

  1. It occupies a specially preserved peninsula jutting into the immense cooling pond for the Florida Power and Light Martin Power Plant, where they prefer solar by day and natural gas by night.
  2. There is a U-shaped Seminole “mound” apparently constructed to detain fluctuating waters from Lake Okeechobee, trapping the seafood catch of the day.
  3. Some Bald Cypress trees there are 700-1000 years old.  I looked up other things dating back so far.  Such as,  about that time the Byzantines did not get along with Bulgarians, so they blinded 24,000 of them.

Being a blog on native plants the responsible Barley Barber Swamp subject  is Bald Cypress,   famous for those conical woody knees poking up from the mud.  Because the knees already have a history in the blog, they get only a short review now, with details here.

Taxodium ascendens 8

The tree’s knees, by John Bradford.

I do not believe Cypress knees to have anything to do with serving as air snorkels to aerate the roots, or for propping up the trees.   I believe their actual function is boringly obvious, that these root outgrowths rise above suffocating water and mud to permit the basic metabolism required to pump sugars, not air (there are no air canals), outward into the underwater roots.   Sort of like the pumping stations situated serially aboveground to propel buried sewage lines.  All tree roots metabolize and pump sugars, but those in better circumstances do not have to come up for air.  Well, that’s how I see it.

cypress old

Around 800 years old.

So then a new topic for tonight.   I encountered “pecky cypress” several years ago, not in a biological context, but rather decoratively.   Today its biology stared us in the face.   Pecky cypress wood is riddled with isolated vertically elongate cavities.

cypress pecky

Pecky cypress in the swamp.

The cavities are the work of wood-rotting shelf fungi, probably best referred to as Laurilia taxodii (Stereum taxodi).  Their identity, classification, and nomenclature is a tangled web beyond the scope of tonight’s good times.     More interesting than their classification is a glaring matter of decay:

Why does the fungus not decompose the wood evenly?    It carves well defined scattered hollows leaving the wood between strong, healthy, and uninfected.  Not a new question.   Back in 1900, before the Wright Brothers, botanist Hermann von Schrenk in St. Louis probed the question for 54 pages in painful anatomical detail.  Anyone reading this would quickly dismiss the notion held by some that the tree and fungus have a symbiotic relationship where the fungus provides water-storage pecky chambers.   There is nothing in von Schrenk’s research, or any clear basis in plant anatomy or physiology for that.

Instead, Hermann found something more remarkable, which it would be a joy to see re-examined with modern techniques.   To make a long investigation short, he found the cavities free of water and to contain brownish dusty material resembling humus in the soil.   By this he meant dark-colored organic acid compounds, not the compost many gardeners refer to as “humus.”   Noting that humus can prevent decay, and citing human remains mummified for centuries in it, von Schrenk thought the fungus transforms wood to humus-like material that coats and kills the fungal strands, thus stopping the infection before it expands far.    The decay holes remain small because they spawn their own termination.

Who knows, and this is utter unabashed speculation, maybe the tree benefits from the peckiness because it lightens the weight of a thousand-year-old top-heavy shallow-rooted giant whose biggest risk to life and limb is toppling.



Posted by on November 3, 2017 in Uncategorized



False-Foxglove, Pretty tho a Little Sneaky

Agalinis linifolia and related species (about 11 species in Florida)

(Agalinis comes from Greek for “resembling flax,” linifolia refers to the linear leaves.)

Orobanchaceae (traditionally Scrophulariaceae)

Heavenly weather today, at long last, so I helped John with his megacool photo guide to local natural areas.  An opportunity to visit Jonathan Dickinson State Park near Hobe Sound, Florida that was.

JD Park

Jonathan Dickinson State Park.

Plenty in flower now, with the fairest of them all being False-Foxgloves with polka-dotted,  yellow-streaked, ticklefuzz-enhanced, purplish blossoms all through a meadow.  What red-blooded bee could resist?

Agalinis looking in

The white rod sticking out is the style and stigma, responsible for incoming pollen.  Behind it you can see 3 (4th one hidden) downturned points. Those are the stamens in two pairs.

The inner flower structure reveals a feature known as didynamous (dye-DYE-neh-mus) stamens, which is a botanical way of saying four stamens in two pairs of different lengths, the members of each pair clinging edge to edge.   Stamens are the pollen-making organs.   The two different-length stamen pairs apparently cater to different types and sizes of bees, and if you look closely the longer pair  is a little different from the shorter pair.    Having the two members of a pair linked side to side demonstrably improves pollen delivery.

agalinis stamens

Flower with petals removed. The long hairless white bar on top is the style.  The two shorter hairy units are the stamen pairs stuck together edge to edge, and of two different lengths and different orientations.

You can’t dig up the prettiest wild flowers in a State Park, so take the next part on faith.   These plants are hidden root parasites on neighboring plants.   The parasitic  root tips grab  victim roots and suck their vital juices just as a tick steals mine.

Gotcha! Agalinis root attacks its prey.    Photo by William Vance Baird.

Now all this begs the question of how the little sucker finds a root to attack, answered in part by recent plant hormone research.  The number of known plant hormones is expanding, and each new hormone has complex roles linked to other hormones.

A hormone family just discovered in the 21st Century is called strigolactones, part of a hormonal-genetic control system with remarkable duties.   This system detects smoke, switching on genes to kickstart seed germination upon passage of a fire.  (This suggests some low-tech experiments, although inconveniently complex variables may strike.)

Continuing the topic of underground detection, how does a plant root beckon beneficial soil fungi, “here I am ready to hook up” in a symbiotic relationship?    Answer:  Roots secrete strigolactone hormones into the dirt to entice fungal partners.    And, yep you guessed it, as biologist Caitlin Conn and collaborators documented in 2015, parasitic interlopers such as Agalinis intercept those hormonal solicitations, exploiting them to find the neighbor who was expecting a friendly fungus, not a sap-sucking parasite.

Agalinis linifolia 1

Agalinis linifolia by John Bradford.

Agalinis clump


Posted by on October 27, 2017 in Agalinis, False Foxglove, Uncategorized


Walter’s Ground Cherry

Physalis walteri in bloom today

(Physalis comes from Greek for bladder. Thomas Walter was an 18th Century South Carolina botanist.)


My first acquaintance with Physalis was long ago in my mother’s garden, Chinese Lanterns (P. alkekenji) named perfectly for the red papery husk around the berry, looking exactly like their namesake.   Occasionally the soft portions of the husk rot away to leave a resistant vein net encaging the fruit.  The husk protects its inner berry and threatens trespassers with poisons.  The air it traps may concentrate volatile hormones to trigger ripening at the right moment.  Consistent with that, Physalis fruits can produce high levels of the gaseous fruit-ripening hormone ethylene.

Physalis walteri 1

Walter’s Ground Cherry, by John Bradford.

They taste as good as the look, that is, as tomatillos, Physalis philadelphica,  little tomatoes so to speak, and the two are related, jointly belonging to the potato-tomato family Solanaceae.   Viva la salsa!

People have eaten Physalis fruits for centuries, the seeds turning up commonly in North American fossil human fecal matter dating back nearly 2000 years.   The abundance of Physalis in American archeological remains suggests pre-European cultivation.  Most Physalis fruits are probably more or less edible, but the plants make toxins, so best to restrict Physalis consumption to tomatillos and other horticultural culinary  selections such as Cape “Gooseberries” as reader Pat Bowman linked in a Facebook comment.  One species used to be illegal in Louisiana as a narcotic, probably based on misinformation.  Eating wild Physalis fruits has reportedly caused dizziness, so not a good idea.  To repeat, there are many species, not all of them tried and proven in the kitchen.   That some are in the culinary world does not guarantee zero risk from unknowns.

Physalis walteri 2

The flower, by JB.

Bioactivity gives Physalis another ancient avenue into human affairs, as remedies for a lot of ailments, including historically to treat wounds and lesions, which is interesting in a modern light as the poisons can snuff unwanted life from bacteria to human cancers.  A widesread weedy species, Cutleaf Groundcherry Physalis angulata, has a rich ethnobotanical history sold now as mullaca powder, touted as good for what ails you.

Physalis angulata plant


Who knows how useful Physalis drugs might be to humans in the future?   One non-human species seems to apply them now.    As biologist Andrea Barthel described,  the Ground Cherry Moth, if I may call it that, Heliothis subflexa (aka Chloridea sublexa), breeds exclusively on Physalis.   Guess where the moth larva grows up?  Within that poisonous fruit husk, hidden from enemies and ingesting the fruit and its cell-killing steroids.  Instead of destroying the moth, the plant toxins protect it from bacterial infection.  Part of the moth’s new immunity is to Bacillus thuringiensis, the bacterium sold in bottles to control garden pests, and whose toxic protein is bioengineered into those GMO crops of such concern in techno-politics.

Physalis walteri 3

Walter’s G.C. by J.B.

Physalis walteri fruit in net (1 of 1)

The fruit in a network of veins


Posted by on October 20, 2017 in Uncategorized, Walter's Ground Cherry


Grassleaf Spurge


Euphorbia graminea

(Euphorbus was a physician in antiquity.  The Gramineae are the grasses.)


This morning John and I photographed Maggy’s Hammock near Hobe Sound, Florida, one of the few great hammock remnants hereabouts.   John’s working gradually on a photo guide to the natural areas in Martin and St. Lucie counties.

Maggy’s  hammock abounds in biodiversity, and over several years the blog has embraced most of the botanical star players, the species you might expect.  So today here is one you don’t expect.

Euphorbia graminea LW

Grassleaf Spurge

Pronouncements in references on the native-ness of widespread tropical weeds always bug me.   Weeds get around.   That’s what weeds do.   Where “native” ends and “invasive” begins is not always clear.   Today’s little weed is indigenous from northern South America into Mexico.  And yet here it is in Florida.  Did it arrive unnaturally, oh say as seeds stuck in somebody’s shoe, or did it arrive without human assistance, oh say, seeds in a bird?   Did Global Warming warm the welcome?

Euphorbia graminea flower head

The “flower” (more precisely, the cyathium), microscope view.

In any case, in recent years the species has popped up  in  Africa, India,  the Pacific Islands, and more.   It is a tagalong in nursery plants, jumping from pot to pot  using explosive fruits to fling seeds like shrapnel.   Many  members of the Spurge Family  pop their fruits,  famously Sandbox Tree, Hura crepitans, and Brazilian Rubbertree, Hevea braziliensis.    But  neither of those grow at Maggy’s Hammock.

The flowering structure, as with all Euphorbias is complex,  to detail another day.  Suffice it to say that the tiny “flowers” about one mm across almost all produce fruits,  hinting that the species can pollinate itself, as many annual weeds do.   That way, a single individual can found a new population.  Handy in the weed world. Also, I witnessed today the world’s tiniest mini-fly visiting the flowering units.

Euphorbia graminea pods1

Big green poppin’ pods and little white “flowers.”

All who attempt to trace the origins of garden flowers wind up mangled by confusion and contradictions.   The popular garden selection Euphorbia ‘Diamond Frost’ is, according to various sources, including especially the authoritative Flora North America, Euphorbia graminea all dressed up.   But by contrast, the usually accurate Missouri Botanical Garden’s Kemper Center classifies it as Euphorbia hypericifolia.  That too, is a common weed, in my back yard.  The resemblance between it at the garden flower is not that convincing to my eye.   And contradicting both, the company that patented the garden selection calls it a hybrid.   So much for Googling.   But a nice insight into how idiot arguments come about.


The white selection is Diamond Frost.  Photo by Cultivar413, permitted use via Creative Commons.


Posted by on October 13, 2017 in Grassleaf Spurge, Uncategorized


Buttonsage, Snowbird Warblers, and Nuptial Gifts

Lantana involucrata

(Lantana is an ancient name for Viburnum, a similar genus.  An involucre, IN-vuh-luke-er, is a nest of leaves around a flower cluster.)


We’re working on a photoguide featuring John’s photos to the local natural areas,  Peck’s Lake near Hobe Sound, Florida, today.  In the scrubby seaside hammock restoration there John and I encountered many crabs and also the Verbena family presenting flowers and fruits in familial synchrony:  Beautyberry, Fiddlewood, Rough Verbena, and Buttonsage all hanging around and showing off together.

Lantana involucrat 4

Lantana involucrata, by John Bradford.

The last-mentioned is always a treat, with fragrant-foliage, pastel flowers having yellow eyes, and glossy purple fruits.

Those purple fruits are birdfood, and the prime customer is the Kirtland’s Warbler.  Any nature enthusiast growing up in Michigan is familiar with this storied traveler nesting in the northern pine woods and then flying far.  The endangered and recovering  bird winters, likewise in pine woods, in and near the Bahamas, where reportedly one of its staples is Buttonsage fruits, although insects are on the menu as well.  Interestingly, a fruit it likes in Michigan is the blueberry, similar to those of Buttonsage.

Lantana involucrata fruits (1)

Buttonsage fruits today.

Today’s shrub provides a textbook example of butterfly-pollinated flowers, which often look like tightly clustered inverted little witch hats in pastel colors, each having a bright-colored eye.  Bingo…exactly Buttonsage, which feeds more species of butterflies than a witch can shake a broom at.

Lantana involucrata flowers


Beyond butterflies, Buttonsage serves pollen to ground-dwelling bees.  And there’s a hint it may do the same for some butterflies, in particular Heliconius butterflies, such as the gorgeous Zebra Longwing known to visit the flowers.  So now let’s climb out on a creaking limb.   Although butterflies are not generally regarded as pollen-eaters, they carry it from flower to flower as they seek nectar.  However, if you are going to lug around pollen,  why not swipe nutrition from it?    Recent research, featuring Lantana, has shown Heliconius buterflies, after collecting pollen on their sticky proboscis, to extract nitrogen nutrients from the grains for “egg production, increased longevity, and nuptial gifts,” in the words of biologists C. Penz and H. Krenn, citing previous researchers.

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Posted by on October 6, 2017 in Uncategorized

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