RSS

What’s the proper side dish for cannibal stew? (Sweet Potato)

30 Dec

Morning Glories

Ipomoea species

Convolvulaceae

John and George missed getting to the field this week, John with house guests, George with the flu and with adult children home.  So we take a lazy armchair look at a nourishing and photogenic genus.  Ipomoea has around 500 member species, with about 25 in Florida natural areas, wetlands, gardens, and Winn Dixie.  This is the genus of Sweet Potatoes (Ipomoea batatas) and of various species significant in ethnobotany, in gardens,  as invasive exotics and weeds, and at rock concerts.  (Remember Morning Glory seeds?, If not, Google.)

Ipomoea indica (by JB)

Ethnobotany first.  Sweet Patooties originated in the American tropics with their cultivation dating back thousands of years.  They sure have gotten around, making their way westward into the Tropical Pacific in pre-European times.  How exactly that came about remains hidden in the mists of history, despite plenty of discussion and conflicting hypotheses.  Our utterly worthless and 100% non-original guess is that they came back across the Pacific with Polynesians who visited South America and then went back.  And this is our segue into another weird story of Sweet Potato relocation, with a Florida connection.

The Archbold Biological Station near Lake Placid is dedicated to ecological research, especially of scrub. Its 1941 founder Richard Archbold (1907-1976) did not earn his glory studying Red Widow Spiders in Florida scrub, but rather as an adventurer, aviator and jungle explorer, especially in New Guinea.  An Indiana Jones kinda guy, he was the first recorded Western explorer to discover the Baliem Valley in New Guinea, home to an isolated Stone Age population lost to the bigger world until Archbold’s 1938 visit.  What a find.  This was the heyday of aviation-borne, National Geographic feature exploration, and the New Guinea folks were cannibalistic and wore scary tusks to make it totally cool. You may now visit as an eco-tourist.

New Guinea Dani Tribesman (Google Images)

Back then a remarkably large lost population of farmer-warriors occupied a high misty jungle valley surrounded by treacherous mountains.  Today perhaps they wish they had not been found, especially because a member of Archbold’s group shot and killed one.  Not a great  ice-breaker.

Now there are a million fascinating aspects to this, but only one ties in to today’s topic: guess what that lost civilization was growing?  Sweet Potatoes, an American plant.  (They had interesting gourds too, but that is a different story.)  But to return to the amazing point with emphatic redundancy: a species from the New World was the primary crop, cultivated with finesse thank you, in the hands of an isolated mountain tribe with no prior western contact.  Dang.  How that came about is not 100% clear.  Biologist Jared Diamond suspects historical Spanish mariners to have something to do with it.  More intriguing (if less likely) is the possibility that the pre-European movement described above extended as far as New Guinea.  Comparative DNA study will sort all that out soon enough.

Ipomoea alba (by JB)

And speaking of weird Sweet Potato redistribution, closer to home, floristic super-botanist John Kunkel Small wrote about Giant-Rooted Morning Glory (Ipomoea macrorhiza) persisting from probable ancient cultivation on Florida Native American middens.  If not cultivated, it was clearly at least a sanctioned “camp follower.” Whether or not the species is “native” in Florida seems unclear (and way interesting), placing it in the same native-or-not category of other midden present-day survivors and archaeological remains as  papaya, red peppers, and possibly the “native” agaves.

For a species most definitely not native, we have Water Spinach (Ipomoea aquatica), which came to us from Tropical Asia, where it is an important and prolific staple.  In the U.S. and elsewhere, however, Water Spinach has become a Category I invasive exotic, floating on the water surface and extending its green tentacles by 10 cm per day.  Today’s invasive exotic may feed and fuel the hungry world someday, so no need to be a hater.

Moonvine (Ipomoea alba) is a night-blooming species with big moon shaped lunar-white flowers pollinated by moths in the moonlight.  It once festooned the Pond Apple forest around the southern rim of Lake Okeechobee.   Earlier observers marveled at its abundance, and it remains marvelous in places.  This worthy vine has earned respect in nocturnal gardens worldwide where white blossoms in the breeze dangling from tropical pergolas may tilt the mood to enchantment and romance.

To flip to the other enviro-extreme, Railroad Vine (Ipomoea pes-caprae) is familiar to Florida beach bums.  The purple funnel-shaped flowers rise from the stems stretching across the salty sand like a railroad crossing the Mojave Desert.  The leaves resemble a goat’s foot.  This indestructible vine survives relentless abrasion as well as beach sun and salt, and has an impressive ability to regenerate from severed stem chunks.  This and other Ipomoea species contain anti-inflammatory compounds of interest in a modern pharmacological context.  If you get zapped by a Jellyfish at the beach, here’s a new idea to challenge the famous ol’ weewee therapy.  No thanks, really, on both.

Railroad Vine on the beach (by JB or GR?)

If we were writing a book we could go on into scads more Ipomoea species, but we’re just having fun here, so let’s quit while it is still fun.

 
6 Comments

Posted by on December 30, 2011 in Morning Glory

 

Tags: , , ,

Bladderworts and Other Bugivores

21 Dec

Drosera capillaris   Droseraceae

Horned Bladderwort (by JB)

Today John and George  explored  a small pond and adjacent Bald Cypress swamp margin in Jonathan Dickinson State Park near Hobe Sound in preparation for an upcoming educational event.   Carnivorous plants ruled today, so here we go on Bladderworts n’ stuff.   We scored a  Utricularia hat trick, encountered three different species all in flower in a small area.  Generally called Bladderworts,  the  genus contains 214 species altogether.

Zig-Zag Bladderwort (by JB)

Flesh-eating plants represent diverse plant families of Monocots and Dicots, and are not closely related to each other.   They have evolved in situations where the main plant nutrient, nitrogen in its various forms, is in short supply,  or where impaired root functions make it hard to take up, or where roots are absent altogether,  as in Utricularia. Insectivory  captures nitrogen in sterile sandy soils, in acid substrates, on epiphytic perches, in anoxic muds, and sometimes in aquatic habitats.  Utricularias look more like Algae than Flowering Plants—until you spot the beautiful flowers.

Genlisea with trap (Google Images)

The Genlisea traps are tubes, topped with two weird  long twisted appendages at the open end.   They look a little like those blow-up arm-flapping tube men they use to draw attention to used car lots and furniture sales.  The armlike appendages have inward pointing hairs.   Varmints swim in but can’t back out, because the hairs are a unidirectional valve,  as some fish traps catch fish.  The Genlisea traps are technically rolled leaves, so it is possible they evolved from simpler ancestors having in-curled blades resembling those of Pinguicula, making Genlisea sort of a “missing link” between simple Pinguicula and the complex traps in  Utricularia.   Perhaps relevant to this, Genlisea species have foliage leaves in rosettes  resembling those of Pinguicula.

Bladderwort bladder with trigger hairs (Photo by Jose Almodovar)

Utricularia traps are bladder-shaped or look like one of those goatskin wine squirt bottles favored by skiers.    The door leading into the bladder has a trap door.  Near the trap door are microscopic trigger hairs.  When the victim jostles the triggers,  the trap door releases and the bladder expands rapidly, sucking in the meal, as a slurp gun sucks in an aquarium fish. The in-slurp happens in a tiny fraction of a second.

CLICK for video

Today’s three Utricularia species are a study of variation within a single genus.   Leafy  Bladderwort  (U. foliosa) lives suspended gracefully in the standing water,  looking at first glance like a green alga waving in the pond.   It builds up huge slippery biomass.   Oddly, the species is distributed in the Americas and in Africa.

Leafy Bladderwort in water (by JB)

The other two, Zig-Zag  Bladderwort (U. subulata) and Horned Bladderwort (U. cornuta), inhabit  moist muds.   They both have fine threadlike leaves hidden in the soil.    They differ in their flower structures:  living up to its name (cornuta = horned), Horned Bladderwort has a long horn-shaped spur on the flower.   Zig-Zag Bladderwort is one of several species in ur area capable of making cleistogamus flowers: tiny flowers that self-pollinate (or somehow develop seed) and never open.

This species has a second quirk.  Where are the photosynthetic leaves?  It has some leaves but not much.  Botanist Wilhelm Barthlott and collaborators, citing earlier research, discuss this species as one of the few “carnivorous” plants that derives energy and not merely minerals from carnivory.

Around our feet, the Bladderworts had competition for the buggy menu.  The wet ground was littered with beautiful tiny Sundews (Drosera capillaris).  The reddish leaves on these are shaped like spoons and are covered topside with long hairs, each hair with a glistening glandular tip.   Insects who touch the tarbaby get in worse and worse as they struggle, until the goo-tipped hairs bend inward and press the corpses to the digestive leaf surface.

Sundew enjoying lunch (Photo by JB)

 
Leave a comment

Posted by on December 21, 2011 in Bladderwort, Sundew

 

Tags: , , , , , , ,

Dull Leaf Coffee isn’t THAT Dull

10 Dec

Dull Leaf Coffee


Psychotria sulzneri


Rubiaceae


Today John and George continued exploration of Mariposa Cane Slough Preserve in Pt. St. Lucie behind Sam’s Club.  Basing our species choice on beauty, today’s looker was the Dull Leaf Coffee, Psychotria sulzneri in full berry.   This species is one of the four Psychotria species in Florida, three of them native, two indigenous to our area.  The other local native is the Wild Coffee, Psychotria nervosa (the term “nervosa” refers to the leaf veins, not to a mental condition).


Psychotria is one of the largest Dicot genera, with over 1500 species around the world in warm climates.   Some, including Psychotria punctata introduced in southernmost Florida, have symbiotic bacterial translucent dots in the leaves.   Some produce psychoactive alkaloids, although the name “Psychotria,” is apparently not a direct reference to drugs, but rather to an ancient belief that species of this genus propped up the psyche, or soul.   Wild Coffees are related distantly to the coffee we drink, and so far as we know, drinking preparations from Psychotria is dangerous (see comments on drugs above).   Psychotria is in the Coffee Family, the Rubiaceae, an assemblage of many thousand species, including wildflowers (such as Innocence), garden selections (such as Ixora), medicines (such as Quinine), and weeds (such as Mexican “Clover”).


To transition into today’s chosen species, Charles F. and Pearl Sulzner were early Miami real estate investors who supported good causes, including botany, especially for the New York Botanical Garden.  John Kunkel  Small, Florida’s preeminent botanist and namer of P. sulzneri,  represented the New York Botanical Garden and was connected to Miami philanthropy.  He knew how to suck up. Charles Sulzner died tragically at age 85 after being clobbered  by a streetcar in St. Petersburg.





The fruits (photo by JB)

The stunning berries (actually, drupes) on Psychotira sulzneri  pass through a bright yellow phase on the way to scarlet, often resulting in flame-colored fruit displays, no doubt irresistible to birds.   We will come back to the amazing  flowers when the species is in bloom.


The most remarkable feature of Dull Leaf Coffee is not so colorful.    Our two local Psychotria species have starkly different leaf coloration.   Psychotria nervosa features high-gloss bright green.  Psychotria sulzneri , by contrast, has a deep green velvet-matte finish, with a tiny kiss of blue.  But why?  That leaf color is not common in the plant world, although it occurs in other species.  Folks with northern wildflower experience know “Wild-Ginger” (Asarum canadense) with similar coloration.    The leaves are also reminiscent of some Hydrangea foliage, or to a couple of grass buffs like us, a wee hint of Blue Maidencane (Amphicarpum muhlenbergianum).    What do all these have in common?  Shade.


To slide into speculation:     Psychotria nervosa is probably glossy as an adaptation to reflect excess sunbeams, just like a pilot’s mirrored sunglasses.    That would not imply an inability to tolerate shade—it can.   Perhaps delicate shade-tolerant photosynthetic mechanisms need that extra glossy sunscreen, just as the pilot’s delicate retinas need protection.





Rubiaceae stipule (photo by JB)

Psychotria sulzneri  is playing a different game.   Its deep sub-green anti-reflective solar panels  look like they are adapted to drink in every photon, allowing the species to flourish deep in the understory, which it does.  Perhaps P. sulzneri has developed its own sun protection.   When you go to the beach with sunblock it doesn’t show.  So much to research, so few opportunities.  Wouldn’t it be fun to be 22 years old, starting graduate school and looking for research projects with a lab and a grant!?


As members of the Coffee Family, psychotrias have a small flap (stipule) between the opposite leaf bases.  The inner surface of the stipule has on it tiny sticky fingers called colleters.  These secrete nectar;  the nectar presumably attracts ants; and the ants presumably defend their botanical sugar-daddy.  Apparently the Mariposa Coffees have escalated their deterrent threat by attracting Eastern Diamondback Rattlesnakes to stand guard.




By the Dull Leaf Coffeee (photo by John “snakes” Bradford)

 
2 Comments

Posted by on December 10, 2011 in Dull Leaf Coffee

 

Tags: , , , ,

King Eupator, Tom Hanks, and Mrs. Lincoln

03 Dec

Hammock Snakeroot

Ageratina jucunda

Asteraceae

Yesterday, John and George had a good time searching  for Mistletoe in the Mariposa Cane Slough Preserve in Pt. St. Lucie.  This beautiful scrubbish hammock is pure nature joy. And it is in the newspaper,  having its grand opening today (12/3) as this is being typed.  It is an example of the great green things a coalition of green-lovin’ friends of the earth can achieve.  Click for Mariposa

The mystery of MCSP is: “where’s the Mistletoe”?   (Phoradendron leucarpum)   At the southern tip of the Oak Mistletoe range, the species inhabits St. Lucie County, and it is reputed to be in Mariposa.  We looked and hunted, but Christmas kissing in the Preserve  this year must occur without Mistletoe.  Those  big old trees are covered with vines, ferns, Spanish Moss; trying to spot the Mistletoe was  too needle-in-the-haystack for us at the moment, so on to more earthbound plant…

Setting aside an orchid or two, the dominant floral displays yesterday came from the Aster Family, starring Hammock Snakeroot (Ageratina jucunda).   Now we digress a moment, but don’t worry, it all comes together.

A more northern species of Ageratina (White Snakeroot, A. altissima)  is the cause of Milk Sickness which afflicts cattle who eat it and people who drink the tainted moo juice.  The disease was epidemic in the early 1800s in the greater Ohio Valley Region, and killed seven people in Little Pigeon Creek, Indiana in 1818, including Abraham Lincoln’s mother, Nancy Hanks (Lincoln).

Hammock Snakeroot (photo by JB)

Ever notice the resemblance between Nancy Hanks, Tom Hanks, and Honest Abe?  It is not coincidence.

Nancy Hanks (from Google Images)

Also in flower yesterday was Jack-in-the Bush (Chromalaena odorata).  If we turn back the hands of time, this species, Hammock Snakeroot, and White Snakeroot all used to be classified the genus Eupatorium before contemporary taxonomists messed with our minds slicing and dicing the genus.  Geezers like John and George have the older Eupatorium names lodged  in our synapses.

Tom Hanks (from GI)

 

The easiest way we know to distinguish Ageratina from narrowly defined modern Eupatorium is to look at the phyllaries (the little bracts around the flower head).  In true Eupatorium the phyllaries are conspicuously of two lengths, whereas in Ageratina they are nearly all equal, with a smattering of odd little outliers.

We like Eupatorium, because the name has soul—for  King Tiberius Julius Eupator Philocaesar Philoromaios Eusebes, better known as King Eupator, who reigned over the Bosporus in the late Roman Empire.

Tell the truth

 
4 Comments

Posted by on December 3, 2011 in Hammock Snakeroot

 

Tags: , , , , , ,

But Rot Might Be Good For You

25 Nov

Ganoderma lucidum

[This week, being Thanksgiving, no field trip.  However, John, who is developing his mushroom skills, visited Seabranch State Park near Pt. Salerno where he photographed the fungus Ganoderma lucidum, and researched it.  He’s the brains behind this post, for which George is the typing assistant.]

The word Ganoderma strikes terror into the hearts of South Florida palm gardeners.  Recently Professor Monica Elliott from the University of Florida gave a lecture at Palm Beach State College describing Ganoderma Butt Rot in palms.  The culprit is Ganoderma zonatum.  Many hardwood species suffer Butt Rots too, and today’s Ganoderma can be a hardwood butt rotter.  If you are Asian, however, “Ganoderma“ has a more positive ring to it.  Stay tuned on that.  First, some boring but necessary taxonomy.

Ganoderma lucidum at Seabranch State Park (by JB)

Fungal taxonomy is messy.  Within a species the variation of morphological forms and the environmental influences on shapes and colors can be bewildering:  “those can’t be the same species!”   Butt they are.  Today’s Ganoderma lucidum is an case in point; seen broadly it is the center of a species complex and is understood poorly.  The entire genus has been an historical classification nightmare, with several hundred “species” named around the world, most of them probably belonging in synonymy (that is, redundant).  Part of the nightmare comes from medicinal principles attached to—and patented with—species names.  The nomenclatural mess got so out of hand that a prominent mycologist in 1994 proposed a decade-long moratorium on naming new species in Ganoderma.   So for present purposes, let’s say Ganoderma is a large worldwide genus of wood-decaying fungi best known as “bracket” or “shelf” fungi,  although the shelflike “conk” is not their only form of spore-producing body, which can resemble a mushroom, although the underside will have pores instead of the usual gills.

Ganoderma lucidum production (Google Images)

Ganoderma lucidum is prominent species in Asian medicine, known as Ling Shi in China and as Reishi in Japan.  Its applications are ancient, diverse, highly commercialized, and embraced by modern medical research.  Among the many traditional applications are treatments for high blood pressure, diabetes,  respiratory disorder, cancer, and fatigue.  One of the joys of botany is seeing traditional medicinal applications carry forward into contemporary therapies.  Mainstream cancer-related Ganoderma research focuses largely on diverse effects on the human immune system.

What struck me about John’s findings is how many different threads extend from the same fungus found around the world:  photogenic “mushroom” in a state park, cousin to dreaded tree disease, traditional Asian medicine, and  potential pharmaceutical.   Every living thing has a story,  yet so often we just rush past and say, “oh, look at the pretty mushroom.”

Apply in the event of Butt Rot

 
2 Comments

Posted by on November 25, 2011 in Ganoderma lucidum

 

Naked Embryos and Dead Man’s Fingers

18 Nov

Black Mangrove

Avicennia germinans

Verbenaceae

This week’s Friday field trip by John and George got nuked by a combination of work obligations, rain, and car trouble.  With reference to the last-mentioned, this post was written in the commodious Napleton Nissan/Kia Service lounge in Riviera Beach, with complimentary coffee and People Magazine.  So we’ll step back in time just a couple weeks.  Black Mangrove (Avicennia germinans) surprised us by practicing dispersal in massive quantities by bare naked embryos.  We found thousands of them in the tidal wash on the beach at the Hobe Sound Wildlife Refuge across the Intracoastal from Tiger Woods’s spread.  Everybody knows that flowering plants usually disperse as fruits or as seeds, but as exposed embryos?  In saltwater?  Yes.  And some were already rooting on shore, making it clear how you wind up with extensive stands of Black Mangrove.

Black Mangrove embryo castaways on the beach (photo by JB)

Googlization reveals this peculiarity to be old hat to mangrove cognoscenti, even being the basis for the specific epithet “germinans.”  But we’re nobody’s cognoscenti, thus our happy surprise at the little embryonic nudists.  It is also old hat to some plant propagators who soak Avicennia fruits to liberate the embryos for sowin’ and growin’.  By the way, the name Black Mangroves refers to the dark-colored wood.

Embryos from Avicennia species can remain viable over 6 months submerged in sea water and can float alive at least 50 km, although most dispersal is local.  The embryos are large, fleshy, and well provisioned before release.  They look like the innards from a giant lima bean.

Having escaped their fruits and seeds, and having enlarged, they  are in a sense prematurely germinated, and in this way vaguely resemble the precocious seedlings dropping from the unrelated Red Mangroves with a big prematurely sprouted embryonic root sticking out of the persistent fruit covering while still on the mama tree.

Inquiring minds may now ask, well, what about the third Musketeer,  White Mangrove?  Its fruits disperse in the traditional fashion—intact—but they have some “pregermination” going on too, as the seeds can sprout inside the fruits during dispersal.  This shared tendency is an interesting tidbit of convergent evolution where three different and unrelated species have all adopted premature germination, in different forms, to meet the challenge of saltwater-drift dispersal.

Dead man’s fingers (photo by JB)

Anyone with much experience hanging around docks has encountered spooky black gnarly “dead man’s fingers” rising vertically among Black Mangroves.    More convincingly than Bald Cypress “pseudo- pneumatophores,”   Black Mangrove pneumatophores have obvious adaptations as root snorkels.

The fingers are filled with spongy tissue suitable for gas exchange.  The finger lengths adjust to the need for air, and lenticels (breathing pores) on the fingers reportedly open and close in response to environmental conditions.

 

 

 

 

 
Leave a comment

Posted by on November 18, 2011 in Black Mangrove

 

Tags: , , , , ,

Gaseous Emanations and Tropical Soda Apple

13 Nov

Tropical Soda Apple

Solanum viarum

Solanaceae

In Allapattah Flats Natural Area yesterday John and George were struck by the conspicuous autumn beauty of a detested invasive weed, Tropical Soda Apple.

Find Tropical Soda Apple in this Gigapan taken by John 11/11 at Allapattah Flats.  (Hint: look near the white posts.)  You can pan around and zoom in and out: Click

Beyond wicked thorns, why is this South American Category I invasive weed the bane of all that’s good?    Those little ”tomato” fruits bear  oodles of hyperviable seeds and are experts at animal dispersal, reportedly moved around by cattle,  feral hogs, deer, raccoons, and other animals, and possibly by birds, as well as in feed, sod,  manure, and other agricultural products, The  spot where we photographed the plant was decorated with raccoon (?) scat.

The weed loves and invades pastures, degrading over a million acres in Florida alone, quite a feat for a South American species unknown in the U.S. prior to the 80s.  There are ongoing efforts to control it with insect biocontrols, hopefully ones not interested in tomatoes, potatoes, eggplants, and many native Solanaceae species.

Cow + TSA = dispersal (and sick cow?)

Tropical Soda Apple differs from other Solanum species in our area by having the young fruits colored like mini-water melons, straight thorns, and petiolate leaves.

Solanaceae are in large part a druggy toxic bunch, despite the edible species, so what about Tropical Soda Apple? Livestock beware! Illness occurs, including brain damage visible upon autopsy.    Cattle do not read veterinary journals; they eat the fruits and scatter the seeds with abandon.  One of the toxins, solasodine, serves commercially as a precursor for steroidal drugs.  It is amazing how little attention there is to human poisoning from such a tempting berry.  The berries are said to be disgusting, which probably has saved children.

The thorns are just plain evil, yet animals do harvest the fruit.  And this ties in with the beauty we beheld yesterday.  The plants were devoid of leaves, no longer very thorny, and festooned with beautiful cherry-tomato-sized golden berries glowing in the late afternoon sun.  They could serve as fanciful holiday trees at the mall, and are eye-catching at a hundred yards.  This otherwise forbidding species apparently lowers its leafy-prickly guard and gooses up its tooty-fruit advertising at seed-dispersal time.  The berries probably become less toxic upon ripening.

The thorny leaves are gone and the golden orbs are ripe for the plucking (but don't) (Photo by JB)

Let’s go a little deeper on that.  Ripening fruits, of which there are many, produce the hormone ethylene.  Ethylene is involved in leafdrop, which is dramatic in the present case.  Bear with us a moment on an academic yet relevant quote from the 1943 Botanical Gazette concerning Soda Apple’s cousin, the tomato.  The title says it all:  “Defoliation of the Tomato Plant as a Response to Gaseous Emanations from the Fruit.”  Plant physiologist John Skok, from the University of Illinois (which Michigan beat yesterday in an ugly contest), tackled a horto-headache with tomato plants: they drop their leaves late in the growth cycle.

The berry opened (photo by JB)

Like Hercule Poirot, he first dismissed some red herrings, diseases and nutritional problems.  Then he revealed the true culprit, in his words,  “defoliation is in part a response to emanations of ethylene or a combination of ethylene and other unsaturated hydrocarbon gases from ripe fruits…”

OK then, ethylene functioning as a hormone induces leafdrop in a species closely related to Tropical Soda Apple.  (In modern agriculture artificially applied ethylene defoliates crops for mechanical harvesting.)  The phenomenon serves a positive purpose in Tropical Soda Apple by removing the thorny leaves while flashing the showy fruits.  Here we have an apparent case of a pre-existing hormonal mechanism enhanced through eons of evolution  to become a specific adaptation for seed-dispersal in TSA.  Not bad for a debased weed!

 
4 Comments

Posted by on November 13, 2011 in Allapattah Flats, Tropical Soda Apple

 

Tags: , , ,

Allapattah Flats and White Pine Barren Aster

05 Nov

 Yesterday John and George went wildflower-hunting in the Allapattah Flats Management Area in Martin County west of Palm City, and found bugs.  Not just mosquitoes, but also good interesting types.

Web in the morning sun (by JB)

Although not arthropod experts, we can match pictures with the best of them, and our creature identifications come from highly scientific picture-book flipping.  Do not bet excessively on them.  We learned that the Female Golden Silk Orb Weaver Spider makes mighty strong silk (which we experienced), is larger than her puny male, and has only a minor bite (which we did not experience) despite her arachnophobia appearance.

Female Golden Silk Orb Weaver (by JB)

 We learned further that the Salt Marsh Moth Caterpillar may occupy Dogfennel (Eupatorium capillifolium) in abundance.  It reportedly extracts toxic alkaloids from Eupatorium, one of its favorite host genera. (Eupatorium toxins killed Abraham Lincoln’s mother, although she probably did not eat caterpillars, and that topic is for another day.)  The caterpillar wiggles nervously when approached, then drops abruptly from its branch in clear annoyance. How does the caterpillar scatter across a large meadow of Eupatorium?  The species can wind-sail on a silky “parachute” when small, and when older they disperse overland.

Salt Marsh Moth Caterpillar on Eupatorium before dropping (by JB)

The adult Salt Marsh Moth is white with dark spots, having some yellow coloration in the male.  It is not particularly a salt marsh dweller.

Let’s get to a plant.  One of the more striking species at Allapattah this week was White Pinebarren Aster (Oclemena reticulata, aka Aster reticulatus), a species distributed mostly to the north of our haunts, and not found much south of Lake Okeechobee.  A quick look at the flowering dates on herbarium specimens shows most flowering is in the Spring or early Summer, then blossoms seem to wane in Summer, with a second blooming period in the Autumn.

Oclemena, yellow phase (by JB)

Here is a perfect example of a species whose flowers change color, placing it in the company of Mahoe Hibiscus, Rangoon Creeper, other “Aster” species,  and scores of  additional examples in many families.    Flower-color-changers seem typically to go from a light coloration, often yellow, to reddish.

This occurs in Oclemena in the disk flowers, the small flowers packed together at the center of this Composite flower head, that is, the eye changes from yellow to burgundy.   This is not likely to be mere decline with age, but rather a signal to pollinators of a change in floral status.  Many flowers signal reward availability to pollinators with changing color.   That color change accompanies diminished pollen or nectar availability is well demonstrated.  Moreover, presumably innate preference for “reward now” coloration occurs in bees, butterflies, and additional insects.  Even more remarkable, researchers have trained butterflies to alter their behavior based on color in relation to rewards.  Pavlov’s Swallowtails.  Yellow is a pervasive bee-advertising color while reddish tones are not.

The "we're closed" phase (by JB)

 
8 Comments

Posted by on November 5, 2011 in Allapattah Flats, White Pine Barren Aster

 

Tags: , , ,

Love Vine

29 Oct

Love Vine

Cassytha filiformis

Lauraceae

Bee on Conradina (Photo by JB)

John and George explored the Hobe Sound National Wildlife Refuge on the shore of the Intracoastal yesterday, encountering millions of Black Mangrove embryos in the beach debris, some of them taking root.  This was interesting because the dispersal agents are tough, food-laden bare naked embryos without benefit of enclosure in fruit or seed.    We saw Dicerandra immaculata in full bloom left over apparently from a reintroduction effort, enjoyed a bee working over a False-Rosemary (Conradina grandiflora) systematically flower by flower, and encountered a pixieland of mushrooms on the scrubby sugar sand dunes.  

The most imposing and conspicuous (fully) living thing there was the Love Vine draped over trees and shrubs, so we must give it its due.  Love Vine is a nearly leafless scrub-loving parasite resembling orange-tinted spaghetti noodles overwhelming its scrubby shrubby victims.  The botanical name Cassytha comes from Aramaic for “tangled wisp of hair.”  The old name “Woe Vine” fits pretty well too.

To remove a common point of confusion, Love Vine and Dodder look alike but are unrelated examples of convergent evolution.   Dodders are species of the genus Cuscuta in the Morning Glory Family, Convolvulaceae.  Several species live in Florida, with a handful of species in our immediate area.    Although resembling Love Vine, they are far less common and tend to specialize on herbaceous victims as opposed to Love Vine’s preference for bigger prey.

Love Vine (image found on John’s camera after he dropped it fleeing into the woods)

Love Vine (Cassytha filiformis) is a member of the Cinnamon Family, Lauraceae.  Love Vine differs from Dodder by having fleshy drupes (vs. dry capsular) fruits, and by having a feature characteristic of Lauraceae: anthers that open by flaps instead of by the usual slits.   You can see this with a hand lens.   A suggestible observer might sniff the membership of Love Vine in the Lauraceae by a faint spiciness when crushed.   Love Vine has its flower parts in multiples of three, as opposed to multiples of five in Dodder.

Our species, one of about 20 in Cassytha, is worldwide in warm-climate coastal areas.  Apparently the fleshy fruits disperse in part by floating, aided undoubtedly by birds and by storms.

The adaptations of Love Vine for parasitism are profound.  The vine adheres to its host with “suckers” (haustoria) that look like something on a space-alien octopus. 

Love Vine haustoria on oak leaf (photo by JB).

You might think it just sits there and sucks, but the invasion runs deeper.   Tissue from the sucker enters the host and spreads into the hosts cambium (living region just under the bark) and/or phloem (sugar-conducting tissue immediately outside the cambium).  It is never a great idea for a parasite to kills its host.  Although Love Vinosis is sometimes fatal eventually, the attack has a built-in host-sparing restraint.  The parasitic tissue invades the cell walls of its host and draws nutrients out of the host cells across the cell membranes, but the parasitic tissue never actually breaks the host’s cell membranes, thus leaving the host cells alive to keep on feeding.  The recurring idea of harnessing Love Vine as a biocontrol against unwelcome plants may be hobbled by the comparatively nature of Love Vine’s attack. 

On a subcellular level, the xylem (water-conducting) tissues in the parasitic suckers have structures often called “graniferous tracheary elements.”  In plain English, the plumbing at the intake zone has a pressure valve involving tiny granules whose function seems to be to control the stream of incoming stolen sap.    The distribution and roles of these poorly known structures need research.

Around the globe, Love Vine has accumulated numerous uses, ranging from body decoration, to medications, to hair promoter, to potential modern cancer therapy.   As is so often true, the plant contains toxic alkaloids, yet is on the menu in some cultures.    And of course, Love Vine is the active ingredient in love potions.    Happy Halloween.

 
4 Comments

Posted by on October 29, 2011 in Love Vine

 

Tags: , , , , , ,

Sensitive Brier

22 Oct

Sensitive Brier

Mimosa quadrivalvis

Mimosaceae

 First,  today’s story is based at Halpatioke Park in Stuart.  Enjoy John’s Gigapan in the park.  You can pan around and zoom in and out.  Click Here

Second, let’s get our Mimosas straight.

Different Mimosa #1:  Most gardeners and botanical garden visitors have touched and crumpled poor neurotic  Sensitive Plant.  That fun species is Mimosa pudica (pudica = shy) and, although not native to Florida, crops up occasionally in the sunshine state.  It differs from all other Florida Mimosas by having just two pairs of pinnae (major leaflets).

Different Mimosa #2:  Mimosa strigillosa, sometimes called Powderpuff or Sunshine Mimosa, is a Florida native and  a commercial groundcover.  It was a 2008 Florida Nursery Growers and Landscape Association 2008 “Plant of the Year.”  This species has a somewhat elongate (vs. globose) flower head and is the only thornless species in Florida.  (The 4th Florida species, Mimosa pigra, is a vining species with thorns and with flat fruits.)

Different Mimosas #3:  Tropical American Mimosa tenuiflora and some other species have psychedelic root drugs used in mind-bending preparations.  As far as we know, the only “trip” you experience from any of the Florida species is stumbling over a vining stem.

Different “Mimosa” #4:  The “Mimosa” tree is not a Mimosa and is irrelevant.

Different Mimosa #5: Is a disgusting cocktail made with champagne and orange juice. Avoid it.

Mimosa quadrivalvis flower heads (by JB)

Now that the pesky  imposters  are marginalized, let’s talk.  Yesterday John and George enjoyed a 70-degree, blue-sky visit to Halpatioke Park and selected Sensitive Brier to feature here.   Mimosa quadrivalvis, the only Florida species with a four-angled (vs. flat) pod, was in beautiful bloom with its highly pink poofy flower heads.  Less attractive but more interesting were its ugly bristly pods.  To older folks, this species may be more familiar as Schrankia,  a persistent form of  nomenclatural brain pollution.  Does Sensitive Brier recoil from probing like a good “sensitive” brier should?  Yes, but less dramatically than Different Mimosa #1.

Thorny ripe pods (by JB)

 

Let’s linger a moment on the sensitivity.  Many Legumes tend to droop their foliage at night.  They are not wilted.  Rather, they “close up shop” by means of little muscles called pulvini (singular: pulvinus) at the bases of the leaves and sometimes at the leaflet bases too.  The pulvinus controls the angle of the dangle in response to environmental cues.  We won’t go far down that technical road, but briefly, the plant responds to the different reddish light tones during the day compared with those at dusk.   Far-red light characteristic of dusk sends a “time to droop” signal to the pulvinus.  The mechanism is related closely to the way long-day and short-day plants determine the season, and to red/far-red  cues governing seed germination.  Take the drooping  reaction, change the cues from light color to touch, and you have leaves that recoil  when a cow comes sniffing around.  You can watch here as a Mimosa goes to sleep thanks to its pulvini.  Click

What really grabbed us, literally, was not the beguiling flower head, and not the sensitive leaves, but the pods.   They are scary, resembling slim barbed torpedoes.  A reasonable observer might interpret the thorns on the pods as protection from herbivores, which of course is probable, especially since the entire plant is armed similarly.  Beyond that, fruits from many plant species apply spines and varied protuberances to cling to passing creatures to aid dispersal.  That’s conceivable with today’s plant.

 

Mess with the pods, and they unzip (by JB)

 

Playing with the ripe legumes we noticed something fun:  if you abuse them, for instance by dragging the spines across fabric, the pods pop open readily along pre-set lines presenting the seeds all lined up like paratroopers getting ready to jump.  It seems that abrasion and tugging on the spines helps open the pod.  Maybe creatures do it sometimes, or maybe the wind helps as the pods grab each other and snag surrounding vegetation suspended on their vines.

 
2 Comments

Posted by on October 22, 2011 in Sensitive Brier

 

Tags: , ,

← Older posts
Newer posts →