RSS

Category Archives: Uncategorized

Indian-Hemp

Sida rhombifolia

(Sida is an ancient name for a different plant.  Rhombifolia describes the leaf shape.)

Malvaceae (Hibiscus Family)

 

Once upon a time, before the era of polyester leisure suits, natural fibers ruled, and Florida was a place to research and grow fiber-bearing species.    Fiber plant importation here predates the European invasion probably, as our “native” Florida agaves arrived it seems at the hand of prehistoric people no doubt to supply strings, hammocks, and fishing nets.    Florida’s first prominent Euro-horticulturist Dr. Henry Perrine introduced more agaves, most notably sisal, now an invasive exotic species.  Dr. Perrine perished by homicide before Florida fiber fun hits it prime.

Urena lobata 1

Caesarweed, a fiber species.   Today’s flower photos by John Bradford.

Fiber species are mainly tropical, and the Sunshine State was home to avid 19th and 20th Century plant introducers.    It is tough to cite the exact time, purpose, and unsub in a plant introduction, so to keep it general, let’s just say some species came to Florida as dental floss.   And, yes, fiber plants have served oral hygiene where there’s no Walgreens on every corner.

An incomplete list of fiber species still in Florida follows:

Bowstring-Hemp (Sansevierias, the “Snake Plants” in pots and gardens, breeders used to hybridize Sansevierias  in search of fabulous fibers)

Caesarweed (Urena lobata, now it sticks burrs on our shirts)

Flax (Linum usitatissimum, also giving seeds to muffins)

Hemp (same species as ganja)

Indian-Hemp (not really a hemp)

Jute (Corchorus species,  gunny sacks and upscale couture)

Kenaf (Hibiscus cannabinus, save the forest, farm paper)

Manila-Hemp (Musa textilis, a banana of all things)

Ramie (Boehmeria nivea, related to the native false nettle)

Sisal (Agave sisalana, and other Agave species)

Yucca (Yucca species)

yucca

This photo published 1893

There are more but lists are for losers, so to get to today’s hot topic:

Sida rhombifolia 1

Indian-Hemp

Indian-Hemp is a classification mess, in a complex of variants you may or may not interpret as separate species.    Native to Florida?  Some say yes, but my favorite general reference, Flora North America, calls it an introduction from the Old World, and I’d not quibble.  Importation from India gave Indian-Hemp its name.  If you want to see Indian-Hemp in Florida, take a walk.  An encounter will likely ensue.

IMG_1475

Indian-Hemp fibers

Every plant species has history in human medicine…it gets boring…but we have finally found the species applied by somebody somewhere to counter every known ailment, from alopecia to zits.  And for those itching to boil and gobble the world of green, be careful, today’s species reportedly causes abortion among other damages.   The species also induces vomiting, but contemporary politics is more effective for that.   All in all, Sidas are chock full of drugs and stuff, with one ingredient especially interesting…ephedrine.

The stimulant ephedrine crops up in human medications, legally and not so much.     By far the best- known botanical source is the genus Ephedra, very weird desert plants having seeds but no flowers, giving the “kick” in Mormon-Tea as well as to the Chinese beverage ma huang, not to mention diet pills, inhalers, and much more.  Ephedra is about as unrelated to Sida as possible, so what the heck is ephedrine doing in our backyard fiber weed?   In any case, smoking Indian-Hemp is a reported use…obviously a nitwit idea.  I wonder if ephedrine or similar alkaloids are behind that dangerous passtime.

To wrap it up with a curiosity, the fruit starts out looking like a pie.  And it winds up with the same fate, sliced into triangular segments, each acting like a separate fruit,  out of one, many.     Sometimes triangular  flower parts (sepals) wrap around the pie from below,  embracing the pie and holding its slices in place.   Although an obvious possibility, I can’t say for sure the embrace is a function of the weather. Today was rainy and gray, and the grip was tight, however.

Sida rhombifolia fruit wrapped in sepals

The fruit with the pie slices hidden by the triangular flaps bent up from below.

Sida rhombifolia fruit pir slices cooler tone

Protective flaps bent back, and the pie slices exposed.

 

 

 

 

 
4 Comments

Posted by on June 2, 2017 in Uncategorized

 

Elliott’s Milkpea Basking in Climate Change

Galactia elliottii

(Galactia refers to milky stems on one species.  Botanist Stephen Elliott lived in Beaufort, SC, where he was first to collect this species.)

Fabaceae (Legumes)

Today’s visit to the Kiplinger Nature Preserve in Stuart, Florida, saw the first big blooming loblolly bay flowers of the season, a relative of tea and camellias featured some time ago in this blog.

Gordonia lasianthus 17

Loblolly Bay, by John Bradford.  All flower photos today by John.

Today is Wednesday, not the usual Friday trip, due to travel plans. Crabs were crab-walking all about, and a black racer popped up for a peep at us.

snake

This was white-flower day, with the loblolly bays,  tarflower, pineland asters, and the plant of the day, Elliott’s Milkpea.

Galactia elliottii 4

It seems to be designed perfectly for where it lives:   largely in pine flatwoods and scrub.  In short, it has to live conditions ranging from sunny to shady,  where fires pass by,  where water is intermittent, and  where the world’s poorest soils strive to stifle growth.  The plants possess extremely log underground runners,  a rapidly growing twining stem able to sprawl, spread and climb over the ground and over shrubby companions,  tolerance for shade or sun alike, and leaves with adjustable positions.    The most noteworthy and most-studied adaptation is its nitrogen-fixing root nodules.

Although most legume roots “fix” nitrogen, that is, extract it with bacterial help from the air and transform it into fertilizer,  this skill seems to matter especially in the sterile world where Elliott’s Milkpea holds forth.     Nitrogen is scanty in the sterile leached white sand of scrub, where much nitrogen fixation is the work of microbes in the surface crust.      Pine flatwoods soil is sterile too…sandy,  often poorly drained,  and with a dark layer that presumably blocks nutrient exchange.

Galactia elliottii 10

For reasons such as these, Elliott’s Milkpea has become a guinea pig for ecologists asking questions concerning the effects of rising carbon dioxide concentrations.     Closely related is the relationship of rising carbon dioxide to  nitrogen fixation, and what better test subject than a vigorous pea living in a natural sand box?

Nitrogen fixation and carbon (dioxide) have a direct link.    The symbiotic nitrogen-fixing bacteria are paid in carbon for their ammonia fertilizer a swap.   So then, a plant using carbon to buy nitrogen might enjoy a boost if given more carbon to trade.    Biologist B.A. Hungate at Northern Arizona University and collaborators studied today’s species exposed to artificially high carbon dioxide over several years.      At first, elevated carbon dioxide boosted nitrogen fixation, presumably an advantage to the pea plants and thus potentially capable of messing with species balance.   After approximately a year, however, the boost disappeared, probably because, especially in awful soil, resources other than carbon and nitrogen became limiting.   I might make my car go faster by putting the pedal to the metal, until an empty gas tank (or a state trooper) become limiting.  What runs low, according to researchers, might be the element molybdenum.

 

 
3 Comments

Posted by on May 24, 2017 in Uncategorized

 

Spanish Needles, Beggarticks

Bidens pilosa

(including populations traditionally called Bidens alba)

(Bidens means two teeth. Pilosa refers to hairiness.)

Asteraceae

 

Wildlife was abundant today in the Kiplinger Natural Preserve where John and I greeted a friendly osprey, fiddler crabs waving their fiddles in the mangrove mud,  a young land crab posing as a giant spider, and a photogenic corn snake too quick for photos.

IMG_1002

Got eggs?

Anyone who knows me knows that I find the rare attributes of common species far more interesting than roaming to see rare species.  It takes work to know the species literally in our own back yards, including Kiplinger.   You couldn’t have a commoner weed than Spanish Needles; they are everywhere, and the yellow and white flower heads decorated the trails (and our socks) today.

Bidens alba

Spanish Needles by John Bradford

We all know this species, if not as a wildflower, at least as the source of sticktights in our shoelaces and pants cuffs.  They have been known to disperse in the clothes dryer from the trousers of an innocent botanist to his spouse’s apparel, eliciting muttering.  The stickers are well designed, a pair of barbed devil horns on the tip of the seedlike fruit.

Bidens alba horns

Ouch

The fruits of this and some other members of the Aster Family have a second oddity, studied in depth by botanist O.J. Rocha in the mid 90s.  It is something you can see easily while walking the dog.   The headlike fruit cluster has two different types of fruits, or intergrading extremes.   Those at the center of the cluster are longer (let’s call them the central fruits) than those toward the edge of the cluster (edge fruits).

Bidens alba fruiting head

Cluster of fruits.  The central fruits are larger than the edge fruits (small one in circle).

The two fruit types have different jobs. The long central fruits  germinate quickly, and are more quickly relocated away from the mother plant.   Their job is to get far away, and spread the species now.

Bidens alba bare middle

Older fruit clusters.  The central fruits are disappearing.  The edge fruits remain.

By contrast, the edge fruits are reluctant to germinate, probably resist taking in water,  tend to require light to sprout, and cling to the mother plant.     Their job is to repopulate the home site eventually, persisting for who knows how long in the soil waiting for the prior generation to perish and open new opportunity.  Their requirement for light is apparently the cue that the parents have vacated. It would be fun and easy to compare the longevity of the two different fruit types buried in the soil.

Ever notice how Spanish Needles always look free of insect damage, even when the plants around are in tatters?   The species is a witch’s brew of toxins, including poisons researched as potentially destructive to human tumor cells.  One ingredient is PHT (phenylheptatriyne).   PHT smites your foes by destroying membranes.  Everything has membranes so the effect is broad spectrum, beating down such enemies as membrane-bound viruses, bacteria, insect pests, probably us, and competing vegetation.  Contrary to advice by those who feel the most interesting thing about wild plants is eating them…a penchant I’ve never fathomed…just fuggedaboutit!  Unless you are the dainty sulfur butterfly using today’s species as larval host.

Bidens alba 2

By JB

 
5 Comments

Posted by on May 19, 2017 in Uncategorized

 

Dragonflies and Plants

Travel plans prevent a Friday fieldtrip this week, so a preemptive strike now a day early.    This week there are dragonflies in the skies, lots of them.    Halloween Pennants. So enchanting, so acrobatic,  and so molested by all our water pollution and its consequences, but no soapbox here.  Keep it fun.

Halloween Pennant Dragonfly 1 (1)

Halloween Pennant.  All still photos today by John Bradford.

Today the mission is to connect dragonflies with plants.   The first obvious thought then is, “do they pollinate flowers?”   Not an unnatural notion  given all the marsh plants with flowers on top, just where dragonflies perch.   Although dragonflies are not often credited with pollination benefits,  the late Dr. Peter Yeo,  go-to botanist for pollination,  suspected dragonflies as likely pollinators for some Xyris.   I’d be an easy sell on that.

Xyris caroliniana 1

Xyris

Even though dragonflies probably don’t deliver much pollen, they will not be denied a role in flower biology.   As anti-pollinators!  Dragonflies are wicked predators while as larvae in the water and as adult insect-gobbling attack copters.    A couple studies over the years have shown dragonflies to reduce pollinator populations sometimes enough to matter.    Not really a “bad” thing, merely a hand in the balance of nature.

Golden-winged Skimmer Dradonfly

A third impact for dragonflies on plants is more subtle.    The big lugs move nutrients from aquatic ecosystems outward to terrestrial systems.  This might add up to significance, given the abundances, sizes, and appetites of dragonflies,  transferring nutrients from their aquatic cradle to wherever they perish, perhaps during massive migrations, or possibly as a bird snack, and along the way, devouring and spreading the remains of insect prey.    Dragonflies can live multiple months.

Blue-eyed Darner Dragonfly 1

Humans can benefit from, even use, the insecto-destruction powers of dragonflies.  They are valued pest control agents in rice paddies, and have been contracted to help control Zeka-bearing mosquitoes. A small number of dragonfly larvae can remove a lot of mosquito larvae from their watery beginnings.

For a wacky interspecific collusion, consider related damselflies whose submarine larva positions itself to promote photosynthesis by algae (Euglenoids) within the flesh of the larva, the larva benefiting from the oxygen the algae emit.

Spreadwing Damselfly

Dragonflies are territorial, although I think you’d have to be one to understand their social signals during short missions darting around interspersed with restful moments perching, then sometimes visibly munching their victims.   As a dragonfly watcher, I have stumbled into a mystery:   leg-waving, encountered repeatedly.     Why a perched dragonfly might wave a leg could be anything from a social signal (my guess) to itchy toes.   If anybody really knows why, the truth has escaped me…and I’ve tried to find out.  Watch the wave in the video below, and make a guess.

FLIT HERE to see dragonfly action!

 

 
2 Comments

Posted by on May 11, 2017 in Dragonflies, Uncategorized

 

Colic Root

Aletris lutea

(Aletris was an ancient grain-grindin’ slave girl, in reference to the grainy flowers.  Lutea means yellow.)

Nartheciaceae (traditionally Liliaceae)

John and I took a happy gander at the Winding Waters Natural Area in West Palm Beach, Florida, this week, a wondrous restoration of a long-abused and neglected area.   If you like wading birds, a must-visit.  There is even a comfortable covered viewing gazebo.     The restoration is still a little fresh …just the place for Colic Root,  waving its magic yellow wands, a little weird and very pretty.     This is a species of wet meadows, wet prairies, and open pine woods after fire.  Fire seems to bring it forth abra cadabra, along with a suite of wet-foot co-lovlies, such as Sunnybells and Painted Sedges.

Take a brief drone flight over the scorched meadow to see Colic Root in the wind:  CLICK

Aletris lutea 1

The Colic Root wand.  By John Bradford.  All of today’s non-micro-photos by John from scattered sites.  Drone video in Jupiter on a recently burned wet prairie.

Schoenolirion albiflorum 2

Sunnybells

Heliotropium polyphyllum 7

Pineland Heliotrope

IMG_0698

Painted Sedge

Aletris species exist only as a handful in the Southeastern United States and a far-distant second handful in eastern Asia.  Given the widespread medicinal uses by ancient-to-modern patients in the U.S. against digestive complaints we’ll call “colic,”   I wonder if the same pertains in Asia.    Most bioactive plant species collect a catalog of historical medicinal applications, and it is intriguing when there’s a pattern to the attributed benefits.   (But do not try…these species come with toxins, and there seems to be historical confusion with similar species.)

Aletris lookung in

Colic Root flowers

Tummy-ache is not the only recurrent application; another is to counter “female trouble.”      I don’t know exactly what that is, but others have speculated plausibly that the demonstrated presence of estrogen mimics (don’t eat the weeds) may explain the old gynecological usage. The plants come armed with diosgenin,  a natural steroid employed commercially as a precursor in making human steroidal pharmaceuticals, including early birth control pills.

Aletris bumps

Grainy, warty, bumpy flowers

Our Aletris has bumps on the yellow flowers, a characteristic known from only one of the Asian species.   When a trait is as striking as those warts,  this blog is duty-bound to speculate.  One with nothing better to do could cook up notions, from blocking light to insect deterrence, but there is a clue:    gumminess.  Not stinky, and they do not pop to release liquid.  They are fairly firm, yet just a little tacky  So here is what I think, not fact, mere speculation.   They gradually over an extended period collectively release a protective varnish onto the outside of the flower.     These are plants of wide open, windy, sun-blazed living hells for a delicate flower.  I’ll bet that sticky coating protects against the oppressive elements.

The bumps come in three basic forms:   1.  Round-topped and sometimes a little translucent.  2. Flat-topped and then sometimes with ragged edges, like a spent volcano. And 3. Erupting like a volcano.  Just guessing here, but it looks like the young round bumps bust open up top to put forth their varnish, leaving the raggedy  dead volcanoes behind.    This ongoing with thousands of bumps in different stages would protect a flower spike for a long time.

Bump round

Round bump intact …the varnish still in there, it seems

Bump erupting2

Material coming forth from bump.

Bump flat top

Raggedy top spent volcano

 
3 Comments

Posted by on May 5, 2017 in Uncategorized

 

Rogation  Floures

Polygala species

(Polygala means “much milk.”)

Polygalaceae

Polygala setacea 2

Polygala setacea.  All flower photos today by John Bradford.

Halpatioke Regional Park near Stuart, Florida, was the venue today where John and I encountered a WWII Vet (repeat:  WWII, do the math on your cell phone calculator) out alone with canteen on his belt and armed with one of those grabber tools cleaning up litter.   Some folks have a sense of purpose.

Polygala rugelii 2

P. rugellii

We also encountered scattered members of the genus Polygala.    Polygala is one heck of a genus…a few hundred species around the world, twenty-some in Florida, several in our general area.    You could scarcely find a more variable and more colorful plant group, our local rainbow including orange, yellow,  violet,  and white blossoms.   The flowers can be single,  or in branched candelabras,  or in congested heads or spikes.    The plants can be an inch tall, or three feet. (In other regions they can be big and woody.)

Polygala lutea 1

P. lutea

That kind of color and variation remind you of any other plant group?    Methinks Orchids, and the flowers do have features in common with Orchids, including extreme bilateral symmetry,  similar  overall shapes,   often a decorated or complex  “lower lip,”  and precision pollination.   At least one species of Polygala reportedly forces the pollinator to enter a tunnel and scrape inward past the pollen-receptive stigma, and then to exit via a different tunnel, brushing over the pollen-producing anthers.  That would not be dismaying in an Orchid, but Polygalas are completely unrelated.

Polygala grandiflora 1

P. grandiflora

Polygala fruits and seeds have odd features.  Most have furry seeds.   I don’t know why but a guess is protection from the ants usually responsible for seed dispersal.  Most Polygala species offer a food packet on the tip of the seed.    Ants drag the seeds with benefits back to their nests for lunch, and maybe the hairy coat deters overzealous munching.    Some species have no ant help, and have the seed hairs modified into hooked VELCRO, apparently snagging fur or feathers of passing creatures.      Additionally, some species have thin wafery wings on the fruits, suggesting a role for wind in relocation.  Most or all of our local species seem to be ant-dispersed.

Po;ygala rhinanthoides Fl Malesiana

Winged fruit, and hairy seed, the food packet at the tip.  From Flora Malesiana.

Because the genus is beautiful,   and has historical virtues, and is in Europe, let’s see what they thought of it in Merry Olde England.  Well, how handy, I have a reprint copy of Gerard’s 1636 Herbal at my elbow.   Now read together from Gerard:

Polygala Gerard

I always assumed the modern name “Procession Flower” for our Polygala incarnata to reference the inflorescence blossoming over time into a “procession” of individual flowers, but, looky there,  Gerard  already had the name in the air centuries ago with an entirely different meaning.

Polygala incarnata 2

Procession Flower, P. incarnata

Speaking or processions, Rogation is the Christian celebration immediately before the Ascension, traditionally observed with processions, apparently enhanced in Gerard’s world with garlands and “nosgaies.”  Wouldn’t Rogation time be soon,  with the Polygalas here in Florida on schedule?

Polygala cymosa 7

P. cymosa

These are bioactive plants, some having wintergreen essence in the roots.   Being worldwide and conspicuous, no surprise they have a catalog of historical medicinal uses, too many to probe here, and not that interesting.    Except for one,” procuring milke in the brests of nurses.”   That would explain the common name we really use for Polygalas nowadays,  milkworts.  I love the sources that say the name has to do with cows in pastures, yea, sure, a pre-GMO BST.   In fact, Gerard goes on to say milkworts to promote lactation date back into ancient times.  Does it work?  I do not know.  But I do know it contains poisons procuring vomit.

Polygala cruciata 1

P. cruciata

So don’t eat the milkworts, just head out anywhere open and moist, and seek out the color.  To quote Gerard one last time, ”these  plants or milk-worts grow commonly in every wood or fertile pasture whereforever I have travelled.”

Polygala balduinii 2

P. balduinii

 
5 Comments

Posted by on April 28, 2017 in 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

 
8 Comments

Posted by on April 21, 2017 in Uncategorized

 

A Mighty (Small) Oak and its bigger buddies

Quercus minima

Fagaceae

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.

Pinguicula caerulea 3

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.

 
5 Comments

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.

 
5 Comments

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.

Sacoila lanceolata 6

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.

——————————————————————

 
2 Comments

Posted by on March 31, 2017 in Sacoila, Uncategorized