Mother Nature’s Hormone Therapy

 

When April’s here and meadows wide

Once more with spring’s sweet growths are pied

I close each book, drop each pursuit,

And past the brook, no longer mute,

I joyous roam the countryside.  (Jessie Redmon Fauset)

 

[Are there deformed frogs in the brook?]

 

Today’s roamed countryside was the Kiplinger Natural Area on Kanner Highway in Stuart, a bundle of habitat diversity tucked into a small package—weedy meadow, brook with baby gator, mangrove swamp, river bank, low pine woods, and marsh.   The usually modest Gallberry was having its 15 minutes of fame with millions of white flowers abuzz with happy bees.  White Pinebarren Aster (Oclemena reticulata) and Elliott’s Milkpea (Galactia elliottii) splashed more white into nature’s garden.  Rabbit Bells (Crotalaria rotundifolia) were at their yellow best, and Smilax reached out with tender new tendrils and its yellow-green “lily” blossoms.

Galactia elliottii (All photos today by John Bradford)

We’ll zoom in (again) on Smilax as an example of plants able to make compounds, phytoestrogens,  that mimic or interfere with mammalian estrogen hormones and related functions.  A lot of natural and unnatural chemicals do that. The “Silent Spring of the 90s,” increasing public awareness of environmental estrogens, was “Our Stolen Future,” 1997 by Theo Colborn and collaborators.

Smilax

There are things to worry about in the estrogen endocrine-disrupting realm.

Thing 1:  Natural botanical “phytoestrogens” can impact animals, including humans for better or worse, an observation not lost on diet- and herbal-conscious writers.   When we talk of artificial estrogens, we’re not merely talking about potentially feminized males (although possible, as in the famous “teenie weenies” on Lake Apopka gators),  but also fundamental developmental disruption and cancers, especially breast cancers.  Hormonal  activity and the altered gene control of cancers are no doubt intertwined.  As two examples of dietary plant-derived phytoestrogenic booboos, A) multiple post-menopausal women have suffered uterine ailments apparently from high consumption of soy products (legumes can be high in phytoestrogens).   And B) a man developed breast cancer after six years of herbal remedies rich in phytoestrogens.

Some observers suspect that traditional plant medicines for reproductive complaints often tend to involve phytoestrogens or similar endocrine-active compounds.  After all, the first birth control pills came indirectly from yams.   And that brings us back to Smilax.

Smilax is a popular trail nibble and as a genus serves worldwide in traditional medicines including several hormonally related problems, including menstrual  complaints, perimenopausal symptoms (for which it is promoted), impotence, prostate enlargement, childbirth, and psoriasis, which has a hormonal connection.   Smilax is a much-touted source of hormonally active compounds..

(Disclaimers:  I am using the term “phytoestrogen” broadly to include compounds that mimic estrogens, or that impact directly or indirectly regulation of the mammalian estrogen-related system.  Also, Smilax has traditional non-reproductive uses too, and of course human history is loaded with attempts to alleviate reproductive ailments.)

Moving on to additional worrisome things:

Thing 2.  My colleague Maura Merkal last week shared a  report on pesticides in South Florida waters:  “Ambient Pesticide Monitoring Network:  1992-2007” (linked below).  Here is a fun fact from the report:  The chlorinated agricultural and lawn-grass herbicide Atrazine turned up at every sampling location.   Did I mention, every sampling location in our general area.   1517 detections.

Crummy, but how does it tie to Smilax?   We’re getting there.  A recent issue of the New Yorker Magazine (Feb. 10 2014)  recounted an epic battle between  University of California researcher Dr. Tyrone Hayes and the manufacturer of Atrazine.   The rub grew out of Dr. Haye’s research conclusions that a profitable herbicide is an estrogen-related source of developmental deformities in amphibians, or let’s call them canaries in the water.

To comfort ourselves we may say, sure there’s Atrazine in all the water, but optimists and vested interests claim the effects are not proven, and the concentrations are low.  (It was not “proven” that cigarettes cause lung cancer.)  There’s been a loud  “Hayes is nuts”  reaction to his research, including assertions that the results can’t be replicated and that his alarm is debunked.  But there are also independent indications that Hayes is not nuts, and there is evidence of human damage from Atrazine in the water.  It would be an understatement to call this dispute controversial.   Interested persons can conduct their own Google research on this remarkable dustup.   (Readers interested in a broad history of inconvenient research in relation to economic interests might enjoy David Michaels’s “Doubt is Their Product.”)

Thing 3.  Now let’s worry that no matter how hormonally pernicious Atrazine may or may not be, there are a lot of additional estrogen-interfering chemicals in the air and water.  Addiitonal estrogen-related compounds haunt the Ambient Pesticide study.  And even if Atrazine is in “low” concentrations now, we’re adding more and more, and what about combined effects of mixed estrogen mimics?  That brings us to worrisome thing #4.

Thing 4:  According to Our Stolen Future and other sources, hormonally-related chemicals can work in astoundingly low concentrations exponentially below what we tend to talk about in terms of toxicity thresholds, such as killing water-fleas.  (“Didn’t kill the fleas, so I guess we’re safe” does not comfort me.)   Hormones and their mimics seem to have chronic effects at levels of parts per billion, or, yikes, even parts per trillion.  But admittedly all very general and murky.

To  return to native plants, why would a natural organic plant be so crass as to make hormonally -interfering compounds?   Plants able to sabotage their herbivores’ baby-making don’t get gobbled.  Human case in point:  Cottonseed oil, containing phytoestrogens, is touted as a potential male oral contraceptive.  Turns out couples in regions heavy on dietary cottonseed oil have trouble making babies.

Are Dr. Hayes and his supporters correct?   As the detractors say, there is no “proof,”  but the fear of Dollarweed in my lawn ranks below my fear of impaired aquatic ecosystems, deformed babies, and adolescent cancers.

 

Notes:

Ambient Pesticide report

More on Dr. Hayes, Atrazine,  and the New  Yorker article

More on Atrazine and people:

Digest this before scarfing down herbal remedies 

Interesting blog on phytoestrogens

New  Yorker article

 

Partridge Peas and Ambivalent Bees

Partridge Peas

Chamaecrista fasciculata

Caesalpiniaceae

Okeeheelee Nature Center is in Okeeheelee Park near the Florida Turnpike in West Palm Beach.  CLICK   The 2.5 miles of trails criss-cross through dry pine woods interspersed with ponds and marshy areas, a pleasing natural reserve in the middle of our urban area.  So John and I went there today with cameras in hand.

Okeeheelee

Each time and place has one standout species.  Yesterday it was Partridge Pea in splendid flower over the river and through the woods.   Looks misleadingly a little like a fern, well, sorta.  More like Sensitive Plant but no, and not that sensitive.  Resembles a Cassia plenty, and has historically been classified as one.  A little weedy, Partridge Pea is adaptable and variable, basically an annual or slightly woody subshrub with ferny compound leaves, butter-yellow flowers, and flat pea pod fruits.  It’s everywhere, especially dryish disturbed sites, but sometimes where it is moist, in the sun or under the understory—-you can’t miss it.  Recently burned places are good places to look.   The species ranges from Florida across most of eastern and central North America.

Partridge Pea (by JB)

This is one of many local species equipped with foliar nectaries to feed ants.  Look on the stalks of those compound leaves for a little nectar gland on each leaf.  The plant feeds ants, and the ants provide Security Services.  Lots of plants and ants symbiose; on the same outing we saw similar glands on the leaf stalks on Bracken Fern, on a Senna at the Visitor Center, on Caesarweed, and on Cocoplum.

The gland is near the base of the leaf-stalk (JB)

The flowers are open just one day.  Pollination is exclusively by bees, and then only those whose “buzz” has the correct frequency to cause the pollen to puff out of pores at the anther tips.  The stamens (pollen-producing organs) are of two lengths, the shorter ones feeding pollen to the bee, and the longer ones depositing pollen onto it.

This photo (by JB) shows the short stamens and the longer ones.  The single structure angled to the right is the (female) style.  Note how the style is angled to the right, and read on.

 

Researchers examining Chamaecrista using electron microscopes have found the stigma (pollen-receiving organ) to be in a small cavity covered in hairs, and to require the “right” buzz for pollen reception.   Preliminary indications (or conjectures) are of a liquid in the cavity that “comes forth” when buzzed properly, able then to snatch the pollen in glue.  (This glue resembles the pollination droplet characteristic of “primitive” seed plants.) The wrong bug carrying the wrong pollen isn’t going to contaminate these very exclusive flowers.

Oddly, buzz flowers tend to have the flowers in an alternating “mirror image” left-right-oriented sequence.  Looking at the flower face-on, the styles (and possibly stamens) are either bent to the left or right.  This link CLICK shows the right-face, left-face, right-face etc. alternation of the skewed flowers.  Check also the link in the notes below.

The alternation pattern is called enantiostyly (ee-NANT-ee-oh-style-ee) and is known in varied unrelated plants.  In at least some species, the left-skew, right-skew pattern is under the control of a single gene, functioning as a toggle.  What enantiostyly is all about is a little controversial, and possibly more than one benefit, and is a matter of current research.   For a short explanation, pollen placement and removal on the bee is precise, and the bilateral application increases efficiency by addressing both sides of the bee.

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Notes:  Another nice link showing the left- right- skewed flowers: CLICK

Even the opening pods have a mirror-image thing going on (JB).

 

 

 

Glade Lobelia

Lobelia glandulosa

Campanulaceae (Lobeliaceae)

 

Lobelia feayana (by John Bradford)

 

Yesterday John and George trekked under the hot sun down a dirt road in the large wetland area west of Jupiter, a zone of marshes, depression ponds, and wet pine woods.  There’s a special treat there—a flowing gurgling glimmering brook with clear water and tiny fish, lined with all your basic wetland plant species.  A natural garden of delight.  (The horseflies too were delighted to have some fresh meat. Come along.)

And no garden is completely delightful without a Lobelia, as lobelias are among the most widespread, diverse, colorful wildflowers and cultivated horticultural selections around the garden globe, over 350 species.  Today’s Glade Lobelia is a pretty blue wildflower reminiscent at a glance of last week’s Scutellaria.  And just as Scutellaria had a gimmick, the scute, lobelias have their own odd flower feature.

Lobelia glandulosa (by JB)

In lobelias, there are two linked oddities:  the flower tube is slit for most of its length, and the five stamens are fused into a tube encasing the style and stigma.   As the flower opens the stigmas are  hidden within the anther tube, making the flower effectively male (pollen producing) at first, then later the stigmas emerge past the end of the tube to render the flower female.    (These features are notably similar to similar structure in the Aster Family.)

This link shows the anther tube removed from a flower.  The style and stigmas are inside the tube  CLICK

Lobelias have hummingbirds, butterflies, and who knows what else, as pollinators, mostly bees no doubt.  In most other flowers the pollinator has to fit within the petal tube, like a car entering the garage.    But in Lobelia, the visitor pulls open the split petal  tube to gain access to inner flower, contacting the anthers or stigmas through the slit.   This link shows a hummingbird probing the slit flower while having its head tapped by the anther-stigma unit.  CLICK

As a student, I remember being wowed at a more northern species, Lobelia inflata, sometimes called Indian Tobacco.  (A dumb name since true tobacco itself was a Native American bad habit.)  The professor said, accurately, that people smoked this species and used it in medicines for the several alkaloid drugs it contains, most interestingly for smoking-cessation and for curbing other addictions.   That was in the 70s, and research has marched on. It turns out the dominant alkaloid, lobeline, interacts with more or less the same brain receptors as nicotine, although they are not similar chemically.  There’s perhaps something potentially useful going on there, and lobeline interferes with the neurotransmitter dopamine.

One of these days I’ve got to quit smoking!

 

Hydroballochory Happens!

Helmet Skullcap

Scutellaria integrifolia

Lamiaceae

Skullcap 3/28. Today’s photos by John Bradford.

In Halpatioke Park in Stuart today (CLICK) John and George encountered a mighty fine mint, Helmet Skullcap, Scutellaria integrifolia.  The species ranges from New England through Florida as one of 350 Skullcap species  all over the world.

Try to find a genus more steeped in medicinal history, homeopathy, alternative remedies, herbal products,  and expensive little bottles, right up to modern scientific medical research.  Skullcaps have served against so many ailments in so many cultures for so many centuries to make a list is as pointless as listing awards won by Elizabeth Taylor.   Just name your favorite malady.   But maybe to curb the fervor for “ingest every wild plant,” Scutellaria extracts cause liver damage, impair membrane functions, and suppress enzymes.

Why name a pretty little wildflower Skullcap?  That stems from the same source as the botanical name Scutellaria.  Let me explain:  The sepals in this and other mints are fused edge-to-edge to make a cup at the flower base.  The proper name for the little cup is the calyx tube.  In this useful link, the tube is labeled, “sepals fused.” CLICK

The defining feature of Scutellaria is that on the outer upper surface of those fused sepals (calyx tube) rises a bowl-shaped shield, or scute (plate).   The scute often looks like a beanie, hence the plant name.

The scutes at the flower bases. Little green “beanies” jutting up from the green cup formed by the fused sepals, the calyx tube.

But why should that wacky scute exist?  To answer that we need a little general background on the Mint Family flower and fruit structure.  We’ve already met the fused sepals, the calyx tube.  As the flower transitions from the flowering phase to the fruiting phase, the petals fall away, the calyx tube remains in place, its scute enlarges, and the fruits remain as four tiny dry “seeds” inside the calyx tube, which is usually more or less horizontal on the old flower spike.   The sepal cup is spring-loaded at the base, so picture a nearly horizontal cup with four ping pong balls inside, attached to a vertical pole by a spring.   When raindrops strike the scute on the top side of the tipped cup, let’s call it now a splash-cup,  the falling drops bounce the cup. The bounce pops the “seeds” out for dispersal.   That’s  hydroballochory, dude.  This link shows four seeds  ready to bounce. CLICK

 

 

 

 

 

Dwarf Huckleberry

Gaylussacia dumosa

Ericaceae

Yesterday John and George experienced Savannas Preserve State Park near Port St. Lucie and featuring marshes, wet prairies, scrub, low pinewoods, and all the associated biodiversity. CLICK to visit.  The area is rich in members of the Azalea Family, the Ericacaceae, including today’s little oddity, Dwarf Huckleberry.     The Dwarf Huckleberry was the show-plant of the day, in full bloom on high dry sandy spots hanging out with its relatives tarflowers and blueberries.

Dwarf Huckleberry. All photos today, except the damaged blueberry flowers, by John Bradford.

Two things about Dwarf Huckleberry deserve attention in Treasure Coast Natives.   Each has an historical component.

Historical Thing 1.  Odd distribution.  If you’d like an example of a case proving species are tough to define, here it is.  Harvard Professor Merritt Lyndon Fernald who reigned as King of northeastern U.S. botany for the first half of the 20^th Century, studied our huckleberry and perceived one species with two varieties distributed eye-poppingly from Newfoundland to very nearly where John and I saw it yesterday.  Fernald dubbed the northern populations Gaylusaccia dumas variety bigeloviana, noting only minor differences between these and the southern variety (var. dumosa).   The truly interesting part was an ecological component, with the populations at the northern end of the distribution mostly in bogs, and those to the south more prone to dry sandy habitats. (It might be worth mentioning that bogs, with extreme acidity, can be “physiologically dry.”   There are other cases of split bog-upland distributions.)

Yesterday at Savannas.

This single-species view prevailed for almost 100 years until a new interpretation popped up in 2007, granting the northern end of the bipolar complex to secede as Gaylusaccia bigeloviana.  The fuzzy geographic border between G. bigeloviana and the remaining G. dumosa runs across the Carolinas.   So in short, a classic botanical situation: a plant group stretched out over a long distribution, with some differences pole-to-pole.   One widespread species with two varieties?  Two species?  Something else?  You decide.  Want to argue? No thanks—pretty much a fool’s argument really.  No matter how you slice and dice it, dwarf huckleberries from bogs in Newfoundland look like plants John and I saw in Savannas Preserve State Park.  (For northward peek,  see p. 5  CLICK)

Historical Thing 2.  Crimes against nature.  Back in 1888 botanist L.H. Pammel—noteworthy as an advising professor to George Washington Carver—published a long treatise on the “perforation of flowers,”  that is, on holes drilled into blossoms by insects to rob nectar, as opposed to entering properly.  Nectar thieves!  One of his examples was, yep, Gaylusaccia dumosa burgled by five species of wasps, as

Related to Huckleberry, these Blueberry flowers have been perforated and robbed. Prof. Pammel would like this photo, which I’ve borrowed from Google Images.

observed at Orlando, Florida, nipping holes in the side of the bell-shaped petal tube.  The circumstances of that observation in Orlando ca. 1888 must have been interesting!  Do wasps consume nectar?  Yes, some do,  including sting-less males of certain species.

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Huckleberry FAQ’s

1. What does Gaylussacia mean?  Joseph Gay-Lussac (1778-1850) was a prominent French chemist.  Dumosa is a specific epithet applied to plant in thickets.

2. How do Huckleberries differ from their cousins, the Blueberries?  Blueberries have a variable number of seeds loose in the berry.  Huckleberries have 10 seeds in the fruit, each seed in a little hard case.

3. Where can I see a modern classification of huckleberries?  http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=113345

Our species, color plate from Curtis Botanical Magazine

 

Saw Grass

Cladium jamaicense

Cyperaceae

John and George failed to hit the wilderness this week for diverse reasons, including a mandatory Friday campus meeting for George, and John completing the revision of our grass web site  CLICK

The website adventure has resembled crossing the Everglades in a Speedo,  bled by typo mosquitoes, wrestling tech support pythons, and sliced raw by Sawgrass.  John did 90% of the work, and the new revision is a breath of fresh air with better info, old editorial sins corrected, updated photos,  and improved performance.   In honor of the occasion, today’s blog must of course be Sawgrass.  SAW HERE

It is the sworn duty of anyone writing about Sawgrass to point out quickly that we’re talking about a sedge, not a grass.  The name is not 100% misnomer though, the “grass” saws with gusto.

All photos today are Sawgrass by John Bradford.

When I think of Sawgrass, I think of the Everglades or maybe picking up cool kicks at 40% below retail at Sawgrass Mills.  SHOP HERE  The big sedge is not just a Florida possession however.   It ranges from Virginia to Texas and into the West Indies;  after all, the name is “jamaicense,” not “floridacense.”  And, oddly, there is a population in Hawaii regarded as indigenous.  Sawgrasses get around.  The “seeds” (achenes) float, and they mature a little fleshy presumably promoting bird dispersal.  With species borders debatable, there are Cladiums from Mexico to northern Canada through Europe all the way to Australia.  (CLICK for one classification.)  Cladium mariscoides, a more-northern species with harmless foliage ventures as far south as North Florida.

Beyond the floating fruits, how does one species fill vast areas, quickly and competitively after fires and hurricanes?  Like many sedges, Sawgrass has rhizomes protected in the moist soil for spreading and regeneration, ho hum.  More interesting is an ability that crops up here and there among  sedges, formation of baby plantlets in the inflorescence, not from seeds but clones of the mother plant—pups or bulbils.  You can see similar clonal babies at the tops of many Agave plants or on “Walking Iris.”  Sometimes the babies take root when their inflorescence bends to the ground, allowing the sedge to “walk” across the land.

The sawtooth leaves give today’s plant its reputation as a bloody gauntlet to traverse.  But why do the leaves have those teeth?  The kneejerk answer is to deter eating, but maybe—just a hunch—there’s more to the story.  What’s the biggest threat to a plant that fills acres of wetland?  Herbivory?  Maybe, but competition from surrounding vegetation, even other Sawgrasses, is conceivably a more pressing issue.   Can those infamous leaf margins slash adjacent vegetation as they lash about  in the wind?

Sawgrass is chiefly a freshwater species with limited salt tolerance.  As saltwater intrusion boosts salinity in some habitats, Sawgrass loses market-share to more salt-loving competition.

The famous competitive threat to Sawgrass is by Cattails which have taken over in places.  A much-discussed contributing  factor is artificially high phosphorus levels from pollution entering the naturally nutrient-limited Everglades systems, tipping the competitive balance.  But life is never simple.   Cattails and Sawgrass share an adaptation to flooded soils – air channels called aerenchyma (air-EN-caw-maw) in the roots bestowing upon both the super power of flood tolerance.   But according to research, Cattails have greater tolerance, and are perhaps more robust to soil toxins.  Cattails are favored, it seems, where water is impounded deeper and longer than Sawgrass prefers.  Of course you could write a book about disturbances to marsh ecosystems and consequences to the species balance.  Chapters in the book would concern salinity, nutrients, toxins, water levels, and fires.  But all of that may be subsumed under the final chapter:  Sawgrass marshes are predominantly coastal, and sea level rise from Global Climate Change may have the last word.  Why worry about a few cattails?

 

Flip-Flopper Flowers

Spurred Butterfly Pea

Centrosema  virginianum

Fabaceae

John and George devoted much of the day to revising our Grass and Sedge web site www.floridagrasses.org (you will still see the “bad” old version), but today was too enticing to remain cooped up inside, so we took a botanical look at the Hawk’s Bluff Trail, a scrubby coastal dune area near Jensen Beach, and part of Savannas Preserve State Park.  Any witness would testify that the flower show today was Butterfly Pea, Centrosema virginianum.  Hundreds in bloom decorated the trail.

These are curious members of the Pea Family, with an odd twist.  To establish comparative context, let’s start with normal pea-type flowers.  There are  five petals (see the diagram, top yellow images).

• A “banner,”  which is a showy billboard rising up above the rest of the flower
• Two “wings” which stick out straight from the center of the flower.   These paired petals can be small or sometimes tough to see.  They are not important today.
• And a “keel” at the base of the flower made of two petals joined to form a boat-shaped envelope, open-side-up serving as landing platform for bees.  The keel contains the business parts of the flower, the pollen-receptive stigma and the pollen-making anthers.   When a bee lights on the keel, the keel bends down, and the stigma and anthers pop up to contact the underside of the visitor.   This sort of normal pea flower is detailed in an earlier blog
  

Now, turn the beat around.  In Centrosema (and in similar Clitoria) the flower is essentially the same but flipped, with the keel on top and the banner at the base, the banner now serving as landing platform. When an insect visits these flowers, the keel with its stigma and anthers is above the bee.

Top: Standard pea-type flower
Bottom: Flipped Centrosema flower

Side view, with X-ray vision, of Centrosema keel and the style hidden within

A similar flip-flop is seen in Orchids.  In a minority of Orchids the big showy petal (called the labellum) rises up just like the banner in normal Pea Flowers.  And the stigma/anther unit (called the column) serves as landing platform just as the keel hiding the stigma and anthers does in a standard Pea Flower.  (Such Orchids are called non-resupinate Orchids.)

The majority of Orchids, however, are flipped 180 to resemble Centrosema, that is, with the labellum (banner) as the welcome mat, and the stigma-anther unit arching above.   (Such Orchids are called resupinate Orchids.)  Here are some resupinate Orchids.   CLICK

You can see the odd resemblance of resupinate Orchids to Butterfly Peas.  And so can so-called “Orchid Bees,” that is, Euglossine Bees, caught in the act occasionally of visiting Centrosema.  BUZZ here  Is the Centrosema floral-flip a mechanism to poach Orchid bees^*?

Those flowers are flip-floppers!

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Notes:

^*Don’t let me over-state the “Orchid Bee” -Centrosema hunch, which has occurred to other botanists before today.  Euglossine bees are not limited to Orchids (and to Orchid lookalikes), and Centrosemas do have a variety of floral visitors.  But still, Orchido-centric bees visiting Orchid-mimicking flowers is fertile hunch fodder.

John and I enjoyed the common Centrosema virginianum,  but there are additional Butterfly Peas in Florida. Centrosema arenicola is state-listed as endangered; most of its range is Central Florida.  Another, presumed to be a garden escape, is Centrosema sagittatum.  (There are similar species of Clitoria also.)

Being good legumes, Centrosemas serve as cover crops,  green manures, and rubber, and as livestock fodder.