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Poison Ivy

Toxicodendron radicans

(The misnomer “Poison-Oak” is applied sometimes to this species, although in Florida that name is probably best reserved for the close relative Toxicodendron pubescens and relatives in the Western U.S.)

Anacardiaceae, the Cashew Family, many of which can cause dermatitis

 

Continuing our month-of-Fridays probe into the botany of the Kiplinger Nature Preserve today in perfect weather, John and I found the plant most interestingly in bloom to be poison ivy.    Too bad it is nasty, because the species has a certain charm and fascinating natural history otherwise.

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Leaflets 3 let it be.   All photos by brave John Bradford.

Poison Ivy is not “a” species, but rather the most mind-boggling complex of Mother Nature’s messy handiwork you can find.   Anyone who wants to reduce botany to simplistic species and easy rules better first look at this perplexing tangle of variation ranging across much of Asia, North America, and parts of Tropical America, but neither Europe nor Africa.      Different people can look into the complex and see different species, subspecies, varieties, and even different genera,  with our well known eastern Poison Ivy more similar to the same species in Japan than it is to all the numerous variants in the rest of the U.S. and Mexico.   The big ol’ mess was sorted out painstakingly by Michigan State University botanist William Gillis on the shoulders of predecessors.  The late Dr. Gillis and I shared the distinction of our careers intersecting with the only botanist convicted of booking  a hitman to murder his wife.

A good segue into Poison Ivy.  The writing on P.I. as a poison are infinite, so to pick the weirdest aspect of that history  I know of, as documented by Gillis, hereyago:  indigenous men in California used the irritating plants to oppress women.  When the men wanted to meet and keep the women apart, one guy would strip naked, be body painted, and run around all crazy threatening the women with wet poison ivy branches suspended around his head.   Who would volunteer for that job?  The hazards are numerous.  A better use of the plant, despite the itch, was in the Netherlands to reinforce dikes. Worked better than a little boy sticking his finger in the leak.

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Would you believe Poison Ivy has a role in ornamental horticulture?    It develops red fall color and contributes to the subtle autumn hues in South Florida.     It has served in that capacity cultivated in gardens in climates where fall color is otherwise deficient.

Poison Ivy has the ability to resurrect dead trees.   The vine climbs hugging the defunct trunk, and way up high decides to branch out like the original limbs on the tree.   From the distance such a tree looks like a very odd species. Here is the vine covering a dead tree in flames. CLICK

We’ve been trying to catch it in bloom, so today was a minor triumph.   The flowers are separately male or female, on distinct plants.    In some locales, the male plants have foliage differing from the females, a weird occurrence.  Why?

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Blooming P.I. today 2/17/17

The flowers draw bees, and Poison Ivy honey is not unheard of.   No thank you. The blossoms mature into little “berries” which are not berries; they are related to and resemble mini-mangoes: lopsided, flattened, and with a “stone.”  As the fruits age, the outer layer separates from the stone leaving a hollow space, and the outer layer can crack open along lines.

To wrap up, one more oddity.  Commonly allergic reactions come from proteins.    Poison Ivy causes a horrid allergic reaction yet its toxin is not a protein.   Oh however can that be?  Apparently the plant’s poison, urushiol, binds and alters proteins in human skin, and then those altered self-protein complexes kick off an allergy, sort of a vine-mediated auto-immune disorder.    The itchy oil is almost a varnish.   It can collect in sufficient quantities on the leaves to dry into a black spotty paintjob, a skull and crossbones reminder.   Fact is, the Chinese Lacquer Tree is itself likewise a species of Toxicodendron.

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9 Comments

Posted by on February 17, 2017 in Uncategorized

 

Shoestring Fern Digs In and Hangs On

Vittaria lineata

Pteridaceae (or Vittariaceae)

(Vitt is Latin for ribbon.  Lineata refers likewise to the ribbon-shaped leaves.)

No fieldtrip today thanks to that killjoy flu epidemic afflicting the building where I work. Trapped at home today recuperating,   I’m stepping back to my native plants class earlier this week where Shoe String Fern entertained the troops

The ferns do look like shoestrings or flattened pine needles. (Or in old Native American names, a giant’s whiskers.)  Many unrelated plants have long ribbon-shaped grassy leaves.  Why would a fern go grassy?    I think it has to do with its lifestyle  dangling from high dry tree trunks, almost always a cabbage palm.

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Hanging from a Cabbage Palm trunk, by John Bradford.

Most plants open little leaf valves called stomates by day during photosynthesis,  allowing gas exchange, incuding watter loss.  Call it plant-breath.  Shoestring Fern can behave in this normal fashion when water is plentiful.  Unfortunately, up on a trunk with no roots in the ground, the fern can suffer a water shortage.

When that hapens, signaled by a stress hormone,  SSF can switch to a water-saving alternative system called C4 photosynthesis, an adaptation most often seen in desert plants.  A palm trunk can be a desert at times.

When they are in their water-saving C4 mode, the ferns close their stomates when the sun shines,  and open them ony at night,  with two consequences:

  1. Closed stomates block evaporative cooling.   This problem might explain the narrow leaves,  being natural heat-radiators  with a huge collective surface area waving in the cooling breeze.  If you can’t cool by evaporation, switch to letting the wind blow through all those strings.
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Natural heat radiators.  By JB.

  1. The second consequence of  day-closed stomates is that carbon dioxed needed for photosynthesis must be  sequestered for use the next day when the stomates open at night.  Inside the fern leaf is porous material where the carbon dioxide probably collects to await the morning sun..

The stomates  hide in two protective grooves under the leaf, where the fern also hides its delicate spore-making organs, explaining why you seldom see spores on Shoestring Fern.

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Shoestring sliced like salami.   The stomates (st) are in the grooves.   The presumed carbon dioxide spongy storing area is labeled ae.  Photo by B. D. Minardi and collaborators.  Photosynthetica 22: 404. 2014.

Moving to another funny ferny feature requires explanation of the fern life cycle.   Ferns alternate between two body forms from generation to generation.   The big normal fern, called the sporophyte,  spawns  as the  next generation tiny green plants you might mistake for moss or algae,  called gametophytes.    And when those reproduce, they re-generate a new  sporophyte.  Round and round: sporophytes beget gametophytes which beget sporophytes and so on.  Chicken and egg.

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Shoestring Fern gametophytes in dry weather on Cabbage Palm Trunk, highly magnified.  New sporophytes grow from these.

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Close up and personal green gematophyte.  Circled area possibly forms gemmae.

All very interesting today’s species, and much more so in its close relative, the Appalachian Vittaria appalachiana.

Vittaria appalachiana lost its sporophyte.  What?   How can a fern lose one of its flip-flopping generations?     It happened.   This species is known only as gametophytes.   But then you ask, if you need a sporophyte to make a gametophyte, who makes those gametophytes?     Answer:  in the genus Vittaria the gametophytes have little breakaway pieces called gemmae (GEM-ee), which can break off, wash away, and allow non-sexual clonal reproduction.

DNA evidence has helped find the missing sporophyte, revealing that the lonely Appalachian gametophyte comes from a tropical American species called Vittaria graminifolia which still has its sporophyte in its tropical habitat in the West Indies and southward.    How its gametophyte, or very close relative,  got loose all alone and far away in North America would be fun to know.  The case of the runaway gametophyte.

Our local Shoestring Fern has gemmae on its gametophytes too, and appears to use them to mulitply its gametophyte population tucked among old leaf base zones on Cabbage Palms or on the moist palm trunk bases.  Good gametophyte habitat seems to be part of the reason Shoestring Fern hangs around on Cabbage Palm.

There may be a second reason.  We think of epiphytes, airplants, as sitting politely on their hosts, perhaps with white knuckles on windy days.    Out fern does more than grip: its roots burrow into the palm penetrating its outer layers to a depth of at least half an inch.

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Outer layer of Cabbage Palm “bark” removed from tree and viewed from its inner surface (aboout 1/2 inch deep).   The “worms” are SSF roots that have burrowed into the soft decaying palm tissue and spread aggressively within it.

Palms do not have “bark” in the sense of a woody tree, but they can have similar spongy more or less dead outer layers.    I do not know if the fern roots ever poke in deep enough to steal sap from the palm, very unlikely, and unknown to occur, but they are not shy about running through the outer layers, possibly deriving nutritional benefit from the palm’s decay, and/or whatever soaks in from rain water and stem wash.    The ferns finds a natural “potting medium” handy for its gametophyte and sporophyte’s roots.

 
16 Comments

Posted by on February 10, 2017 in Shoestring Fern, Uncategorized

 

Hottentot Fern

Thelypteris interrupta

(Thelypteris comes from Greek for female fern.   Interrupta probably refers to the “interrupted” creeping rhizome holding regularly spaced leaves.)

Thelypteridaceae

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All photos by John Bradford

Today John and I devoted today to a close look at Jack in the Pulpit rising and flowering in the lengthening days, in the deepest darkest swamp we could penetrate.  Having just covered that species two weeks ago, today’s spotlight shall shine on a friend of Jack’s, Hottentot Fern, locally encountered mostly in swampy realms.

Every time I see Hottentot Fern two thoughts cross my mind:

  1. Thought 1 is, “what an attractive fern.” Some today were as tall as a person, but usually they are about thigh-high. The fronds are a little leathery, distinctively hairless or nearly so, and with the clusters of spores cases forming a pretty embroidered stitch inside the leaf margin.
  2. Thought 2 is, “how in the world did a fern in a south Florida swamp wind up named Hottentot?” Hottentots are residents of arid regions in Southern Africa.   I’ve got a theory, highly speculative, and based merely on hints.
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The clusters of spore cases, caled sori, run around just inside the leaf margin.  Each cluster has a little cover called an indusium.   The individual spore cases appear as tiny black dots exposed beyond the edge of each indusium.

To solve that mystery, seeing the human name Willdenow attached to the fern is a hint. Carl Willdenow was a botanist interested long ago in plant distributions.   Does our fern have an interesting distribution?  Yes,   thinking of it as a Florida fern is so parochial…it was discovered in India, grows in tropical Asia,  inhabits the  American tropics, and yes, is in African plenty, including southern Africa where Hottentots would have known it growing along streams.   Ferns aren’t that common in the desert, so perhaps they know it well.

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The overlapping fern and human ranges help explain the name, but did Hottentots have a special interest in our fern?    It is unlikely to have medicinal importance, but look at those beautiful black spore case clusters under the leaves.  Rich black spores.

Fact:  Hottentots used face paints derived from diverse sources.   Fact:  They used fungal spores…so why not fern spores as well?   May never know, but there is one experiment to try.  Next week John and I will spore paint our faces and take selfies.

 
9 Comments

Posted by on February 4, 2017 in Hottentot Fern, Uncategorized

 

Jack in the Pulpit

Arisaema triphyllum

(Aris is an ancient plant name.  Haima is Greek for blood, alluding to blood stains on the leaves of certain species.  Triphyllum refers to the three-lobed leaf.)

Araceae

 

John and I experience botanical addiction to the hinterlands of Kiplinger Nature Preserve, where this morning we tiptoed across the impenetrable Red-Maple-Poison Ivy Swamp and explored a vast isolated scrubby pine woods beyond the pale of human visitation…really.  Guarded on all sides by a formidable moat of water, mud, fallen trees, vines, and swamp.  Where can you go in Florida and see no sign whatsoever of human activity?

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Desolation

Red Maples suggest swampy woods farther north, where a favorite spring wildflower is Jack in the Pulpit, an oddball ranging from Canada southward to our area.   Isolated patches in Martin and Palm Beach counties are among its southernmost outliers.   We encountered Jack preaching in the Kiplinger mud.   Almost every wildflower fancier in the eastern U.S. and Canada fancies this species, and so do many gardeners.

The pulpit is a specialized leaf called a spathe.  It wraps around Jack very much like an old fashioned covered pulpit in some  churches.

Jack is a spadix,  that is,  a vertical spike dotted at its base with many tiny flowers.   Having a spathe and spadix is characteristic of the Aroid plant family, containing such favorites as Anthuriums, Calla “Lilies,” and Spathiphyllums.

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By John Bradford

The flowers on any given spadix  are usually either all male, or all female, although occasionally mixed.     To make it weird,   the individual plant’s sex can change from year to year.   What determines the “sex of the year” remains murky despite repeated studies.   Bigger plants tend to be female  in contrast with smaller male plants, although there is environmental influence beyond mere size.    At least one researcher suggested that a female plant depletes its stored nutritional reserves by making fruits, so the following year it switches to the less demanding male role.

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Jack exposed!  Male flowers at bottom.

What comes next needs more research.   The narrative is based on today’s species plus additional Arisaema species.   Not all researchers agree 100%.  So the following account is a semi-consensus likely to be accurate, still…no guarantees.

Although various floral visitors are on record, the plants seem adapted primarily to fungus gnats as pollinators.     Fungus gnats feed on fungi, so why hang around Jack in the Pulpit?  Jack has B.O. and smells like fungus.    The bare upper spadix emits a false-fungus gnat-lure fragrance.    Jack is a false prophet.

Gnats come looking for fungus.   If they enter the pulpit (spathe) surrounding a male spadix, they drop to the floor where pollen collects and get pollen-dusted.   At the base of the spathe is an exit door to let the gnats fly away bearing that dusty pollen.

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Male pulpit,  stage left.   Female on the right.   Follow the gnat drawn to the false fungal fragrance.    The gnat escapes the male spathe through the door on the floor, and moves on to the female spathe, where it meets its end after delivering its pollen load.

When the gnats enter the spathe around a female spadix they fall in again, this time brushing their pollen onto the female flowers deep in the spathe.    The gnats yet again drop to the floor, but this time there’s no back door. They give their lives to complete the flower’s sexual cycle.

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You can see the exit hole on the bottom left of the pulpit.

Is the plant carnivorous, benefitting nutritionally from its decaying victims? If so, nobody has shown it so far.

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9 Comments

Posted by on January 20, 2017 in Jack in the Pulpit, Uncategorized

 

Firebush has Burning Needles

Hamelia patens

(Hamelia honors naturalist Henri L. DuHamel du Monceau.  Patens means spreading.)

Rubiaceae (Coffee Family)

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Firebush.  Not taken today.  In fruit now.   Although memory fails me in some cases, all or most of today’s non-microscope photos are by John Bradford.

Today John’s and my Kiplinger  activity centered on photo equipment rather than exploration,  making this a good occasion for Firebush.  This colorful, drug-bearing shrub or small tree will ring bells with gardeners beyond those dedicated to native species.

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As with most species that slip into mainstream gardening, Firebush over many years has wandered at the hand of humans around and far beyond its broad range from South America to Florida, divvied up into cultivars in far-flung nurseries, and redistributed willy nilly.  Its garden history is as willy as South Africa and as nilly as China.

My first encounter with Firebush was in the Caribbean, not Florida.    This sort of mixed up globe-trotting pattern is obviously standard for any given garden species.   I’m going to leave its cultivation to the innumerable websites concerned with growing stuff.  To summarize the fine points of cultivating Firebush: plant it, go away.

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Or let the birds plant it for you, dispersing seeds from the pea-sized berries.    As is true of many species, the fruits mature through a red phase, then black, the two colors often clustered close together.   The plant world is rife with red and black juxtaposed as an attractant color combo for birds.    If you think about it and watch, you find red and black together in seeds, fruits, and flowers.

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Let’s go a little more obscure into the secret life of Hamelia.  Firebush belongs to the Coffee Family, and like its kin, the shrub has paired leaves (or leaves whorled in 3’s) with a triangular flap called a stipule on the stem between the leaf bases.   Many plants have stipules, but that triangle between the leaf bases is a Coffee Family specialty.   When the twig is young, those triangular flap stipules clasp the baby stem tip before the leaves grow.

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Stipule, triangular flap between two leaf bases.  The bud has grown and the stem is elongating behind the stipule.

 

This will help.  Picture the boy’s head as the stem bud.  The triangular sides to his hat are stipules.  CLICK

In many Coffees, the stipules hide a palisade of brown micro-teeth called colleters.    The colleter secretions presumably feed protective ants,  and/or protectively varnish the young bud tip under the stipular hat.

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This is Wild-Coffee with a stipule removed to  reveal the brown glandular colleters.

 

Oddly though, in Firebush the colleters are either missing or too inconspicuous for me to find.  Instead, the Firebush stipules have a wet-looking glossy inner surface sealed tightly against tender stem tip.   As the tip elongates, the stipules remain on the side of the lengthening stem awhile, eventually to wither and drop.

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Firebush stipule.No colleters apparent.  Instead the inner face (exposed) is wet-looking and sealed tightly around the bud by the two lips you see along the edges.    The (removed) bud was in that glossy groove.  A tight fit.

The protective mechanisms get weirder.  Many unrelated plants develop microscopic needle-shaped crystals called raphides inside their cells.    Did you every carry an armload of prunings to the compost heap, only to suffer a burning sensation on your exposed forearm?   Might be those little needles doing their job.   For decades, I (and many others) assumed the raphides to work merely by pricking the flesh, and then maybe melting into irritating acid.    But no…wrong…here is yet another example of the newly emerging complexities of the green world.

Biologist Kataro Konno and collaborators in 2014  documented the ability of raphide crystals to inject protein-destroying enzymes when they penetrate.  They give the victim a toxic shot, or a thousand of them!  More  precisely, the tiny pricks punch holes in cell membranes, allowing the toxic enzyme associated with the raphides to enter the victim’s cells.    Punji sticks.

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Raphides from Firebush.  They look lke pickup sticks.

Flip over a leaf and look at the corners where the side veins join the main vein.    With a magnifying glass you can spot kinky white hair tufts.   Those nests, called domatia, presumably house predatory mites on  duty defending the foliage from leaf-bothering mites.

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Firebush domatium, guardhouse for predatory mites

And speaking of mites, Firebush is a key player in research concerned with flower mites catching an inter-blossom lift from pollinating hummingbirds.  (Firebush benefits from many pollinators, including butterflies, especially where hummingbirds are scarce.    In its truly  tropical range Firebush seemingly depends mostly on hummingbirds for “the birds and the bees.”)   Flower mites are parasites able to steal pollen and nectar from the blossoms they invade.    Bad news for Firebush!    In some studies, those microscopic arachno-rascals have reduced the pollen and nectar substantially.     They come, they raid, and then fortified on pilfered booty they reproduce, only then to hop into a hummingbird’s nostrils airborne to the next bush.

the end


Extra notes for inquiring minds…

For  taxonomy within the species,  written by  botanist, Dr. Thomas Elias,  who revised Hamelia back in the 70s and then revisted Hamelia patens as a cultivated complex far more recently.   CLICK

Persons interested in more depth on the hitch-hiking mites, CLICK

Penetrating article on the raphide needle effect:   CLICKITY CLICK

 
5 Comments

Posted by on January 13, 2017 in Firebush, Uncategorized

 

White Stopper

Eugenia axillaris

(Eugenia honors Prince Eugene of Savoy.  Axillaris no doubt refers to the axillary flowers and fruits. The axil is the place where leaf base meets stem.)

Myrtaceae, Eucalyptus Family

This week’s back-to-school frenetic frenzy prevented John’s and my usual leisurely Friday fieldtrip, but no problem,  my native plants class launched a new semester yesterday, and one of the species we learned is a species of mystery.    Today’s attempt may have more questions than answers.

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Today’s photos by John Bradford, some taken in Kiplinger Preserve.

White Stopper is one of several stoppers native to Florida, representing one of the world’s largest plant genera, Eugenia, if  interpreted broadly.

White Stopper is a fine fixture in hammocks and native plant gardens around here, and is lovely with deep green leaves having purple petioles,  and potentially massive displays of white frilly flowers followed by red-then-black birdfood fruits.

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Stop and look at those fruits a moment, they vary weirdly.   Most are smooth and “normal,” reasonable looking glossy berries.   CLICK for normal.   Some are lumpy, warty, and mis-shaped.   Compare the ones below with the “normal” photo.

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Raisins?   Or under the influence of gall-makers?

That could be a matter of age or of growth conditions, but the deviations can be extreme.   Some of the fruits are  off-the-charts, grotesque, and sometimes hard and dry.

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See what I mean?  The fruits can be seriously deviant.

Although I’m not sure where age and conditions end and gall-inducing pests start, Eugenias and relatives in general suffer from insect-induced fruit galls.   Anyone who habitually eats the related Surinam-Cherry may spit tiny larvae from between the teeth.

The abnormal WS fruits bothered Miami botanist Walter Buswell back in 1946, who said of today’s stopper: “often with few or many woody galls in place of the fruit.”  It will be interesting to slice open the berries from now on, especially the weird ones, and see if they are merely raisins, or if somebody’s home within.  There’s a poorly told story hiding here.

Another White-Stopper oddity is their fragrance.  Crush the leaves, and the smell isn’t powerful, despite membership in the Eucalyptus Family.  Stand next to one, and your sniff may disappoint.   But stroll on a hot day through a hammock where the species hangs out, and you may whiff a vague “skunky,” or “earthy” aroma, not unpleasant.  Reminds me of the fox cage at the zoo combined with freshly tilled soil.

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Purple petioles

Why would a plant smell sort of musky, or earthy?  The perfume industry is grateful for plant musks.   Much easier to obtain than civets, and we want cruelty-free cosmetics!  What’s  musk anyhow?   There’s no single definition, sort of like pornography, it is vaguely defined but you know it when you smell it.   So alluring.   Put it in the perfume and stand back!  To over-simplify in the interest of you continuing to read,  plant musks are blends of volatile (easily evaporated) large organic molecules.  OK that is enough chemistry.

Cuban chemist Jorge Pino and collaborators in 2003 identified 42, count ‘em, named volatile molecules released from the leaves of Eugenia axillaris.   Repeat, 42.   Holy stinkpot!  And even more adrift after release when they meet the sun, air, and each other. Among the 42 are compounds used as fixative in perfume, as fragrance in marijuana, as medicines,  as giving beer its hoppy essence.  Some are described as smelling “musty” and “earthy.”  That smelly arsenal exists to counter infections, infestations, and miscellaneous pestilence.

The reason some people smell the shrubs and others fail is probably in part a matter of when the foliage unleashes its  chemical warfare.   True enough when warm, but there may be more to it than heat.   In this connection, the leaves have tiny translucent dots underneath, reasonably guessed to be hotspots where the P.U. sequesters.

 
11 Comments

Posted by on January 7, 2017 in Uncategorized, White Stopper

 

Carolina Willow oozes goos

Salix caroliniana

(Salix is related to an ancient name for Willows.  Caroliniana is geographic.)

Salicaceae

Premature post-plop this week due to attending the Orange Bowl in Miami tomorrow preempting usual blog composition time.    Go Blue. You can’t spend much time in Kiplinger Nature Preserve, or anywhere near water wordwide without Willows.    There are over 500 species just about everywhere.  This is the third Willow appearance in the blog.    In earlier episodes CLICK  and CLICK we looked at them as sources of salicylic acid.   Two remarkable facts reappear from hosts of blogs past.

  1. Salicylic acid (named for the Willow genus Salix) is essentially aspirin.  Ancient patients around the world chewed two Willow sticks and called in the morning.
  2. Salicylic acid exists in Willows and in all or most other plants as an airborne hormone functioning to “spread the word” of pathogenic attack, urging nearby plants into a defensive mode.   Paul Revere hormone:   the fungi are coming!    The signal travels on the breeze.  Now, a plant would have no “interest” in warning other separate inviduals.  Plants have no kindly intentions so far as I know.  BUT:  Perhaps Willows super-produce salicylic acid because some species spread into huge clones, in a genetic sense a single individual sprawled across the marsh.  When you “warn” the surrounding stems you are warning yourself.
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Carolina Willow by John Bradford

Today a new chapter on Willows,  their sticky oozings.    To ease into the stickum, first a little evolution.   If botanists of an earlier era got it right,  the history of Willows seems to go like this:

Once upon a time, the ancestors of Willows depended on insects for pollination, possessing the trappings associated with buggy blossoms:   fragrance, colorful petals, nectar.   But somewhere along the line ancestral Willows ditched all that and switched to wind, as is true of many trees.

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By JB

Modern Willow flowers look like standard wind-flowers, arranged into spikes (called catkins) with no petals to turn a passerby insect’s head.    Usually the male and female flowers are on separate trees—so often seen in insect-pollinated species.

That’s all good until we notice bees and wasps visiting the Willow flowers with gusto.   Buzz off. You guys aren’t supposed to be here!    Or could it be that Willows decided ixnay on the indway, and returned to insect-pollination?   That’s what botanists think.

What’s weird about resuming the insect habit is that Willows had already given up their advertising equipment, and  remade it “from scratch.”    Look closely, there is color, not in petals as in the distant past, but now in bright yellow anthers (pollen sacs) on the male flowers.   The female flowers do not have much color, however.    Scent?  The male flowers smell sweet.   If the females do, my sniffer has trouble detecting it.

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Male flowers, fragrant and with yellow anthers.  Bees simply adore yellow.  JB

New bright color.  Scent.  Does it seem the male flowers have regained more bug-attractiveness than the females, at least as a human sees it?   The male flowers do appear to draw a lot more insects.   The male bush can be buzzing.   Not sure why this disparity is so, but it seems (repeat, seems) maybe the male flowers vastly outnumber the females, and thus load up hordes of insect pollen-carriers,  only a fraction of these required to visit the relatively sparse female flowers.

The interesting part of an insect dependence mulligan is renewed nectar.  Both the males and females have it, but oh oh, here is a problem, isn’t nectar usually made on petals or on the  ovary of most flowers?    Yes, but Willows have no petals, and the bee-loved males have no ovaries.    In both the males and females each flower has one or two nectar glands outside  flower’s base, oddly positioned.     The oddness is best explained as new, replacement nectar glands accommodating the late return to feeding insects.    They are substitutes.     Let’s say I throw away my stylish Macys hat, then move to the hills and get cold ears.   I  make a new hat from skinned skunk.

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Male flower rising verticallyat the center of the photo.  Associated leaf tilted to the left.  Nectar gland, outside the flower, yellow, on the right.

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Female flower.  Nectar gland on the left, yellow.  The flower tilted to the left above the gland.  The hairy item on the right is a stem.

Now to stretch it all to the point of pain.  No evidence.  Just a hunch about how the trees managed to remake nectar glands at the flower bases.   Willows are glandular all over.   You want a gland, we have plenty.  There are so many glands on a Willow, providing the flower bases with new ones seems “only natural.”      Read on:

Most notably, every tooth on every sawtooth leaf has its own gland, a hundred glands per leaf, also on the stipules.  Botanists have pondered the purposes of these leaf-tooth secretions, and maybe they attract defensive insects to the foliage, or maybe they deter herbivory, and perhaps they coat the tender leaf margins in protective varnish, and ossibly they secrete excess water.    Perhaps combinations of these functions  differ in different species.   Who knows, maybe the leaf goo helps volaralize that salicylic acid.    In any case, Willows are oozing all over, so  if a part of the plant, flower bases for instance, needs nectar to get back into the insect game,   it may have been pre-ordained.   Repeat, this is a hunch and only a hunch.  (A good one though.)

salix-leaf-tooth-gland

Leaf sawtooth tip with yellow gland on the right.  Did the new flower-base glands come from something like this?

In one intensively studied species, the tooth-tip gland extrudes its product in a thin filament, like linguini out of a pasta machine.   CLICK HERE to see the spaghetti.

Why does it do a thing such as that?

salix-caroliniana-5

The opned fruits (mature female flowers) releasing seeds in “cotton.” By JB

 
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Posted by on December 29, 2016 in Uncategorized, Willow secretions

 
 
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