Noyau Vine

Merremia dissecta


It is with extreme sadness, I must note the passing of our wonderful blog friend Mary Hart.  Some readers may recall her participation in the blog a year ago and more from Worcester in the U.K. where she had been confined to a wheelchair.   Mary was a botany student in my program during the early 90s at the University of the West Indies, Barbados, and was an avid horticulturist and naturalist, smart as a whip, a basketball fan, and a ton of fun.  She is missed. 

After some time away, John and George revisited Seabranch State Park yesterday to preview a nature walk we plan to lead there tomorrow.   Greeting visitors at the park entrance, climbing in the low scrub vegetation, is a weedy-looking morning glory vine with some history and mystery.   (Most of what I know that history comes from a 2007 article in the journal Economic Botany by the late morning glory expert Professor Dan Austin.)

Noyau literally means, “nut.” In the Caribbean context the term refers to almonds.  You guessed it. Noyau vine is almond-ish.   Not that that’s good for those who think the joy of wild plants is to eat them; essence of almond is associated with cyanide, just as in apple seeds and those laetrile apricot pits.

Noyau Vine (By John Bradford,  this and the next are file photos not taken yesterday)

Noyau Vine (By John Bradford, this and the next are file photos not taken yesterday)

But a little toxicity never gets in the way of plant uses; in fact poisonous-ness flags medicinal applications.  As Dr. Austin documented,  Merremia dissecta has served the variety of purposes in traditional medicines, flavoring, and even as a root food in Argentina, presumably prepared to free the entrée of cyanide.

As with so many bioactive plants, the historical medicine cabinet is boring and redundant, although ointments against skin ailments ring plausible as cyanide-based toxicity obviously may grant antibiotic powers.

What I find more interesting than the individual uses is a broader implication based on the breadth of uses:  People move useful plants around, and this creates complications in branding species as native or not native to any given region.  There are many cases perhaps where such designation should not occur, and we have before us a good example.   When you don’t know, you don’t know.

Merremia dissecta closeup

Is noyau vine a Florida native?  Look in different books and find different answers.  Should we rogue it out with malice as an abominable invasive exotic weed?  Or is the vine a native ethnobotanical treasure?   Without the possibility of certainty,  Dr. Austin tilted toward the latter, and I’m aboard on that.

Given that the species is native around the Caribbean Basin, there’s a fair chance it arrived in Florida free of human help.  To make little more interesting, of course there has been commerce around the Caribbean Basin for a very long time before Columbus spoiled the fun, although the degree of involvement of Florida in pre-Columbian Caribbean commerce is an open question.   Could it have come in a canoe or around the Gulf of Mexico from points south and west?  Sure.  We can ask the same about papayas, agaves, and more. William Bartram encountered the vine in Florida in the late 1700s.  How did it get around so early?  Non-human dispersal?  Native Americans?  Early Europeans?  A combo?

Whenever the original geographic limits,  noyau vine now with the help of people is worldwide in warm climates, and even some that aren’t so hot: Pennsylvania, Arizona, Africa where it has developed an ethnobotany of its own, and even Australia as a weed.

On tomorrow’s nature walk, we won’t eat any, but we might smash it up and see if it smells like almonds.


Posted by on March 19, 2015 in Uncategorized


Get Out Your Umbrella!   A Meteor Smacked a Flock of Bats!

 Trentepohlia aurea

Green Algae

John and George are both leaving town awhile, locking the blog in limbo for a few weeks. One last shot before bon voyage.  Then no more clutter in your in-box from us.  We’ve been exploring Seabranch State Park near Hobe Sound, Florida for several weeks. Arguably the most diverse region there is a dense wet coastal swamp.  Today’s odd plant hangs out in the swamp, although the photographs come from other sites.

What would you think if the rain fell bloody red? It happens. To some folks blood from above portends the end of times.  To others a meteor obviously whalloped an unlucky flock of bats. Not that far fetched after all, a meteor strike did eliminate the dinosaurs 60-some million years ago. To the more scientifically sanguine, red dust picked up somewhere by atmospheric currents explains the coloration. Case closed.

Trentepohlia on tree bark

Trentepohlia on tree bark

A microscope might help.  Aha!  Those reddish raindrops aren’t Sahara dust, but rather a soup of living cells.  But, oh my,  as a team of physicists—repeat, physicists—concluded, these don’t look like any cells we’ve seen before, so they gotta be extraterrestrials. Space brood is serious stuff!

Trentepohlia on a palm trunk

Trentepohlia through the microscope

More or less this scenario played out in connection with red rainfalls in India in 2001…and before…and after. How often does a botanical garden solve a newsworthy scientific mystery?  What do microbiologists do when presented with cells of an unknown type, at least before DNA technology? Culture them, especially when they look like spores.  Can you imagine the potential consequences of culturing alien spores?  There’d be some finger-pointing among the oozing survivors!  When the Tropical Research Garden and Research Institute in India risked unleashing the galactic fungus, the hatchlings THANK GOODNESS were earthlings— the common alga Trenepohlia.  Here is a report on a similar event in Sri Lanka. CLICK

Trentepohlia up close on tree

Trentepohlia up close on tree

If Florida had a  tropical climate we too might experience funny rain. We have plenty of Trentepohlia, and you’ve probably seen it, at least if you stroll through swamps. It forms golden yellowish carpets on tree trunks.    Some Trentepohlias are not content to enjoy a mere free perch—they can parasitize their tree host, although I don’t think our Florida Trentepohlia aurea plays that nasty game.

Closer view


Trentepohlia is a Green Alga in a classification sense, even though it’s not colored green. The color deviation comes from high dry life on tree trunks.   An alga out of water needs sunscreen. The orange pigments are related to the carotenes in oranges and carrots, giving Trentepohlia its sunshine hue, and making its spores resemble bat gore, which I’ve never seen.


Posted by on February 17, 2015 in Trentepohlia



Mama Mia – Could That Be Chia? (In Seabranch State Park!)

Salvia hispanica


Something John and George did not expect in Seabranch State Park today was ch- ch- ch- Chia. It’s a perky mint similar to the native wildflower Salvia occidentalis although with the blue flowers crowded into a dense spike instead of spaced out widely.

Salvia hispanica.  (All photos today except the Chia pet by John Bradford.)

Salvia hispanica. (All photos today except the Chia pet by John Bradford.)

Everybody who has ever watched TV or battled their way through Walmart of course has seen Chia pets, maybe Homer Simpson with a rakish hairdo of Chia seedlings. I hope you’ve grown one at some point. We sometimes use them in my plant physiology class to demonstrate plant responses to light of different colors. They bend it like Beckham towards blue light.  The seedlings do not resemble the adult mint.


If you’re up on contemporary healthful eating trends, you probably know Chia seeds attributed with healthful benefits.

Salvia hispanica today

Salvia hispanica today

To be technically correct, there are multiple closely related and very similar species of Chia. Though sold under the single name Chia even by a single company, the seedling species sprouting on the ceramic pig is usually or always Salvia columbariae, whereas the dietary Chia seed is today’s Salvia hispanica.

Chia, with a pet

Chia, with a pet

Both grow in arid western North America, so maybe it’s not severely dismaying to find Chia blooming merrily in the sandy sun-baked arid scrub in Florida.  Chias have history as snacks and meds in pre-European North American cultures.  It seems the perception of the seeds as healthy and energizing dates back thousands of years. A fad diet for the Mayans. Anyone who has slathered the seeds on Elmer Fudd’s noggin knows that when moistened they expand as a gelatinous mass. So naturally the traditional applications include poultices and plasters. Perhaps more interestingly, and I say this as an ophthalmology patient, ancient peoples with a painful particle in their eye, or maybe an intrusive bug, would pop a seed under the eyelid to let the expanding jelly could capture the irritant for easy extraction. Who would think a novelty is sold on TV would have a serious time-honored history?

Salvia occidentalis

Salvia occidentalis

The time-honored history may turn into a time-honored future, if you can believe material put out by the purveyors of Chia products.  According to the main supplier, and I know no reason to doubt them, farming Chia has become an industry in Uganda, where relief from hunger and poverty is life-giving. Photographs from Africa look exactly like the Salvia hispanica John and I enjoyed this morning.  I don’t know if the claims are the whole truth, or if there’s an undisclosed downside, or if there is self-serving exaggeration, but at first glance it seems that buying a silly Chia pet at Walgreens may put food in the mouth of a child on the other side of the world.


This video is of interest.


Posted by on February 13, 2015 in Chia


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Golden Club

Orontium aquaticum

Araceae (Aroid Family)

Today John and George planned an upcoming botany walk in Seabranch State Park near Hobe Sound, Florida.  We didn’t have much chance to explore new flora and fauna, but no problem, because this is February, time to visit the swamp. There are three reasons I stomp the swamp in February: 1. The low water level allows access to regions nasty during the rest of the year.  2. The bald bald cypresses allow light to the forest floor, promoting green life galore in what would otherwise be the deep dark shadows. A time for bromeliads, liverworts, mosses, seedlings, and marvels to find.  3. No bugs.

Bright spots down in the wet are golden clubs, unique members of the Aroid Family.  I’ve been fascinated with these showpieces ever since I was a student, and for over a decade have enjoyed a population near my home in Jupiter along brackish Jones Creek. With no solid data, I suspect this to be the southernmost population in eastern Florida.  The plants grow directly in shallow water or very near it.

Golden clubs today in Jones Creek, Jupiter, Florida

Golden clubs today in Jones Creek, Jupiter, Florida

Orontium is a genus with just one species distributed mostly across the eastern United States from Massachusetts to Florida to Louisiana. Oddly, one or two fossil species are known too.  The plants are so odd and beautiful that botanists Robert Godfrey and Jean Wooten used a drawing of one as the frontispiece in their classic manual, Aquatic and Wetland Plants of Southeastern United States.

What fly could pass this up?

What fly could pass up this bad boy?

And now a nod to the name. A reasonable person might think,  “these are golden clubs, and oro means gold,  well that makes sense.” But according to contradictory reliable research, the name comes from the Orontes River in Syria, with ancient myths, legends, and history, including a different plant the ancient Greeks called by a name similar to Orontium.

Humans have eaten the rhizome and the seeds.  And humans have gone over Niagra Falls in a barrel.   Bad ideas IMHO. Like other Aroids, GC bristles with calcium oxalate crystals.  Lots, and calcium oxalate can nuke your kidneys.    I’m not convinced repeated boilings make it as pure as the polluted snow just because folks who want to eat nature say so.  It you want to eat Aroids, why not go to Publix and buy Malanga Root?

So what’s so weird about golden clubs? Start underground. How many plants do you know with a vertical rhizome? The rhizome is about the size of an upright hotdog, which is a corndog,  buried far down in the swamp mud, and it creeps deeper with time.  The roots are contractile, that is, rubber bands to pull the rhizome down out of harm’s way ready to sprout another day, or to wash ashore far away. Offhand, the only vertical rhizomes on other plants coming to my mind are on ferns.  By the way, another native species with contractile roots is coontie. Golden club leaves look like broad blue-green straps with tiny parallel veins.  Like a duck, water rolls off in sparkling droplets.

Like the hood on a well polished Corvette.

Like the hood on my Bentley after Jeeves waxes and buffs.

The best is yet to come, the flowering spike. First a quick lesson on the Aroid Family.  Aroid’s are known to gardeners and Home Depot shoppers as, for example, anthuriums, caladiums, colocasias, calla lilies, spathiphyllums, and many more.  Native plant enthusiasts might be familiar with arrow arums, sweet flags, and additional species.  Bring some of these to mind, and in your mind’s eye you will see a flowering spike called a spadix in association with a modified leaf called a spathe.  On those red florists’ anthuriums the spadix looks like a bumpy cigarette;  the spathe is that waxy scarlet leaf alongside it. Usually the spadix is not showy, and the spathe is the colorful flag. Or to phrase it for us native plant buffs, Jack is the spadix in the pulpit is the spathe.

The spadix.  Twenty-some wee flowers visible.

The spadix. Twenty-some wee flowers visible.

In golden clubs the vestigial spathe is effectively absent. The spadix has taken over the showy function. It puts the golden in golden club. And what pollinator is lured to that goldfinger?  Apparently species of flies, with room for more research.

The pretty yellow spadix has numerous little flowers embedded in it. Toward the base of the spadix the flowers are bisexual, and toward the top the flowers are male. The bisexual flowers mature into a blue-toned fruit with one seed. The seed is separated from the fruit by a layer of Jell-O of unclear significance. Maybe the goo  gives the fruit buoyancy.  Maybe it sticks to a bird’s foot or to a passing gator or to the leaf on a waterlily.

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Posted by on February 6, 2015 in Golden Club


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Hat Pins, Isoetids … and bassackwards gases

Eriocaulon decangulare, E. compressum


John and George enjoyed getting out into the piney forest today; after a chilly dawn the day turned spectacular.  We planned a group walk through a scrubby pinewoods zone in Seabranch State Park. Most of today’s sightings have already entered this blog, so we’ll drift to the marshy area near the swamp where we’ve spent much time lately. (OK, we got lost there.) (Really)

Ant nest in marsh.  Crematogaster atkinsoni?

Ant nest in marsh. Crematogaster atkinsoni?

Hello there

Hello there … who bumped our nest?

As an aside due to John getting us into ants, in every sense, here is some ant biz.   In marshy places (this photo from the Cypress Creek Natural Area) are ants in big papery nests resembling hornet nests, and presumably safe above the high water line.   They seem to be Crematogaster atkinsoni, known to behave this way in Florida.  But don’t bet the (ant) farm!  This is a plants blog.

Attractive in the midwinter sunshine are species of Eriocaulon and similar genera in the Pipewort Family. They go by several English names: Hat Pins, Pipeworts, Bog Buttons.  Some folks hitch the different English names to individual genera, but the species all look too much alike for single handles to stick to single species.  The flower stalks truly do look like hat pins, the plants standing from a few inches tall to knee-high depending on the age, habitat, and species.

Eriocaulon compressum (by John Bradford)

Eriocaulon compressum (by John Bradford)

Now consider briefly a separate group of aquatic plants, the genus Isoetes, also known as quillworts.  There are plenty in Florida but not in our immediate haunts. The reason for an intrusive Isoetes non sequitur is to explain the name “isoetids,”   defined as plants resembling Isoetes not as genetic relatives, but as unrelated species sharing a peculiar aquatic growth form.  They look like slightly succulent grasses.  The plants have air channels in their leaves and roots, and have roots clustered intimately with the leaf bases. The root mass is disproportionately large relative to the foliage.

Ten-angle Pipestem, the root mass is intimate with the leaf bases, and there's a lot of root. (By John Bradford)

Ten-Angle Pipewort, the root mass is intimate with the leaf bases, and there’s a lot of root. (By John Bradford)

The isoetids have a unique life style to go with their characteristic life form.  The most abundant and thoroughly studied example  in our area is the so-called Ten-Angled Pipewort,  Eriocaulon decangulare. The similar Eriocaulon compressum has the same structure.

Eriocaulon compressum with hanger-on

Is this a tuffet?  Eriocaulon compressum with comfy guest

If you’ve read through the boring blah blah blah this far perhaps you’re waiting to see the shockingly unique life style unveiled. Here we go:  In second grade we all learned that plants absorb carbon dioxide through their foliage to let photosynthesis manufacture sugars. But today we learn that is not the whole truth and nothing but the truth.

Ten-Angle Pipestem roots, showing air channels.  The following photo shows the same root cut open.    Gasses pass through the reinforcing cross-supports.

Space worms?  No,  Ten-Angle Pipewort roots, showing air spaces. The following photo shows the same root cut open. Gases pass through the porous reinforcing cross-supports.

Eriocaulon decangulare root cut open

Eriocaulon decangulare root cut open to show the air channels

When you spy a plant with big puffy air channels in its leaves and roots, it is natural to assume a ductwork system open to the clear blue sky.  Those roots need help down in the mud!  But no—wrong, or partly wrong.   Here’s the problem. Many isoetids live completely submerged with no opening to the air.   Ooops, we have the airshaft upside down—-they are exchanging gases through the roots.

Ten-Angle Pipewort root-stem-leaf junction upside-down.  The fluffy material around the margin are inverted leaf bases.  The porous white center is the inverted stem base with its air channels.  At 2 o'clock a single inverted  root enters the system delivering CO2 immediately at the leaf bases and the stem air-channels.  (The thin thread at the tip of the root is a vein left behind when the spongy exterior was stripped off.)

Ten-Angle Pipewort root-stem-leaf junction root end-up. The fluffy material around the margin are leaf bases. The porous white center is the inverted stem base with its air channels. At 2 o’clock a single upside-down root delivers CO2 immediately at the leaf bases and at the stem air-channels. (The thin thread at the tip of the root is a vein left behind when the spongy exterior was stripped off.)

A completely or partially submerged plant lives in stinky goo with plenty of decay going on down there. The roots absorb carbon dioxide from soil microbial activity, bacterial waste gas,  sending the CO2 upward to the leaves for photosynthesis. And waste oxygen escapes down and out through the roots.

This creates the possibility of symbiotic relationships with soil bacteria happy to “breathe” that waste oxygen exiting the roots, and eager to make carbon dioxide to enter the roots.  Maybe those bacteria are even decaying material the plant produces.  I’ll bet that’s happening with Eriocaulon, but am not aware of research showing it in that genus.  Gas-exchange symbiosis with root bacteria is, however, documented in Isoetes itself.  Just think, the entire cycle of life, a mini ecosystem, all in one cubic foot of soil. Maybe.

Ten-angle pipestem flower head (by John Bradford)

Ten-Angle Pipewort flower head (by John Bradford)


Note.  For a deeper look: Raven, J. A. et al.  The role of CO2 uptake and CAM in acquisition of inorganic C by plants of the isoetid life-form: a review, with new data on Eriocaulon decangulare L.  New Phytologist 108: 125-148. 1988.

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Posted by on January 29, 2015 in Eriocaulon


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Blackberry Jam

Rubus (subgenus Rubus) species


Seeking botanical good times in the Seabranch State Park swamp this week and last, near Hobe Sound Florida, John and George just can’t stay out of the swamp, though the mosquitoes may shift that obsession.  John shot a gigapan panoramic image of the mire. (See if you can find me mooning the reader therein.)  Also underfoot were germinated fern spores, more properly known as fern gametophytes, a pretty picture for today although not a topic to explore right now.

Fern babies (gametophytes). By John Bradford. These are about 1/4" across.

Fern babies (gametophytes). By John Bradford. These are about 1/4″ across.

Some of the more eye-grabbing and pants-grabbing specimens are blackberries, in full bloom in January.  Let’s give them their due.  I’ve seen blackberries called a “taxonomist’s nightmare,” but that would be a taxonomist who feels that variation must conform dutifully to a human concept of distinct species. I see blackberries a little differently—as a taxonomist’s dream come true, in the sense of a complex dynamic pattern of organization that couldn’t give a hoot about human preconceptions.

Blackberries (By JB) (Old picture, out of season, not taken this week.)

Blackberries (By JB) (Old picture, out of season, not taken this week.)

Nobody can say how many species of blackberries exist, because they do not sort into traditional species.  (Allow me now for convenience to expand the conversation to embrace blackberries, raspberries, and other close relatives making us the entire genus Rubus.)  Worldwide there are perhaps 700-1000 “species” of sorts, but more interestingly there are also thousands (repeat, thousands) of widespread genetically identical clonal variants, hybrids, possible ancient cultivars, and sundry evolutionary offshoots, including strains with abnormal chromosome numbers.    (In short, pseudo-species separated by small genetic differences arising in a moment by cloning, as opposed to true species evolving gradually by accumulated genetic processes.)

At least four population characteristics make blackberries so devilishly interesting:

1. Everything eats them. As the most delicious food on earth, blackberries feed everything from rodents to raccoons to bears to birds. I once had a golden retriever who enjoyed berry picking.  The creatures move them all over the place aided by little piles of natural fertilizer. This might help explain why so many “types” of blackberries are so geographically widespread.   As an example, cloudberry  (Rubus chamaemorus) circles the globe at northern latitudes, wobbling as far south as Long Island.

2. Everybody eats blackberries. As long as there have been hunter-gather humans they have certainly hunted and gathered blackberries.  Blackberry seeds dot coprolites. (The Coprolites were not an ancient mesopotamian kingdom.) Blackberries long long ago were probably ancient camp followers thriving on waste heaps near human settlements, where humans could go select, perpetuate, and spread their favorite strains, probably creating ancient cultivars. You can be sure that our ancestors helped stir the blackberry genetic pot bringing different variants together, inadvertently producing hybrids, and moving them around.

3. Many blackberries reproduce asexually. They clone.  Many form non-sexual seeds genetically identical to the mother plant. This skill allows minor genetic variants, hybrids, and clones favored by bears, birds, Neanderthals, or the climate to expand their populations and spread.

4. Species of Rubus can be careless about their chromosomes. “Normal” plant species (with very many exceptions) have chromosomes in pairs. But blackberries and their relatives sometimes sport multiple chromosome sets and other chromosomal aberrations. You can get away with that when you reproduce asexually, as the main problem with screwy chromosomes is a thwarted sexual cycle. And blackberries are happy to hybridize.

Blackberries are in bloom now.  Look like little roses, don't they?

Blackberries are in bloom now. Look like little roses, don’t they? Photo taken this week.

So let’s sum up the messy situation. Here you have a group of plants moved around by every living thing and monkeyed with by every prehistoric human.   Mobility brings divergent evolutionary lines together, providing chances to hybridize, which blackberries are so willing to do. Hybrids on average have a rough time facing the real world, unless they are able to clone asexually; oh yeah, did I mention blackberries do that…and then move around again by crows or Cro-Magnons just to stir things up more.

One way to tackle such a complex situation is to grab one thread and yank on it. Let’s do that for our local blackberries. Even that’s not so easy to do, as you may understand from reading this, because a glance at different references reveals the expected disagreement as to what species of Rubus live in our local counties. Let’s go arbitrarily with one modern reference and pull forth three species names: Rubus cuneifolius, R. pensilvanicus, and R. trivialis.  Are any of these locals fuzzy to define or otherwise involved in genetic mischief?

Rubus cuneifolius is a nice “diploid” (with paired chromosomes) species, or is it? Strains with chromosomes in sets of three and four are reported. One sign of taxonomic confusion within a species is synonymy, that is, the existence of additional names interpretably pertaining to that species. I got bored and quit counting after finding 18 synonyms, including the “Rubus dixiensis.”  Makes me want to whistle.    

Another interesting measure of messiness is finding documented hybrids involving a purported species.  I quickly found five and quit counting.  One of them is especially intriguing. Our Rubus cuneifolius is in South Africa an invasive exotic, and seems to hybridize with multiple African species, most saliently with Rubus longepedicellatus.   These two species have spawned what’s known as a hybrid swarm.  The swarm is a geographically widespread series of novel strains not belonging to either parental species.  “Shake-n -bake”  instant species!

Some books say we have Rubus pensilvanicus, others that we have R. argutus.   I sure don’t want to quibble on this question, because the whole point of this post is to underscore the murkiness.   So easy to be expert when simplistic!  Botanical life gets more complex than “either-or.”  Rubus pensilvanicus is no clean-living species.  On the U.S. West Coast, it has generated a hybrid mess with at least one western species, a pattern reminiscent of our sordid South African story.

OK then, what about Rubus trivialis…do we have one true blue species here?  Naw—guess what one of its hybridization partners is, our own Rubus cuneifolius, the same species that mixes it up in South Africa fools around here in Florida with R. trivialis.

Blackberry branch (by JB)

Blackberry branch (by JB)

So when John and I snag in blackberry bramble and say “oh rats,” is it Rubus pensilvanicus, R. argutus, R. trivialis, R. cuneifolius, or none of the above…or a mix of the above?  Or a mix of the above and more?  (I did not label the photos.)

BB Foliage (by JB)

BB Foliage (by JB)


Posted by on January 24, 2015 in Blackberries



Pallavicinia – Liverwort

Pallavicinia lyellii


Today when John and George went botanizing it was nippy, so we felt no surprise in finding the perkiest plants to be a species native as far north as New Brunswick, not suffering from today’s chill. This is the most widespread species you’ve never noticed. Ranging from Canada into South America, out to California, and across the world to Europe, Asia, Australia, and Africa, in other words almost everywhere.

Being that widespread of course Pallavicinia lyellii visits varied habitats with an overall affection for wet acid situations under broadleaf trees. This is exactly where we found it in Seabranch State Park abundant throughout the largely hardwood-dominated swamp at the east edge of the park, a botanical museum of ferns, mosses, lichens, and  liverworts.

Not every reader will be familiar with liverworts.   They are related to mosses and are among the most primitive land plants on earth. They are the oldest known land plant fossils, dating back 473 million years. A look at certain liverworts and a peek at similar green algae makes it easy to believe that the land plants evolved from the green algae, as they in fact did.  I don’t want to go too far down that technical road today. Suffice it to say that liverworts and their relatives have no roots, no veins, poorly (or un-) differentiated leaves or stems, no flowers, no fruits, and no seeds.  They look like seaweeds and stay close to the water.

Leafy liverwort

Leafy liverwort

There are several thousand species of liverworts worldwide divided into two basic types. One group, called the leafy liverworts, resembles mosses by having stems and leaves, although the plants are usually even smaller (you need a hand lens), flat, and with round leaf blades. Look for them on tree trunks and wet hummocks mixed with moss.   Today’s feature species belongs to the other major group, called the thallose liverworts, these consisting of almost nothing more than what looks like a wet green leaf spread irregularly on a wet surface, often mud or decayed log.

Pallavicinia lyellii  liverwort with gametophyte (green) and sporophyte (the thread). By John Bradford

Pallavicinia lyellii liverwort with gametophyte (green) and sporophyte (the thread). By John Bradford

As you can see, John captured a beautiful portrait of Pallavicinia lyellii with its leafy seaweed plant body.  The ruffly little cabbages on the foliar surfaces are the female egg-making apparatus. The sperm-making structures are on separate male plants. The brown cap on the delicate white thread is the spore-making system (sporophyte). It makes the spores that blow way to re-establish the liverwort all the way from here to Timbuktu. Spore-making plants such as fungi, mosses, ferns, and liverworts often have wide windblown distributions.

What does the name liverwort mean?  The wort part is just an old word referring to an herbaceous plant. The reference to liver is more telling. This dates back to an historical dogma called the doctrine of signatures, which attributed plants with benefits according to their appearances. So a plant resembling a fetus was good for birth, birthwort, and lungworts were beneficial for your lungs, and liverworts are liver medicines. I’m not completely sure what the resemblance to the liver is.   I’ve heard two explanations: Some liverworts are lobed in a way resembling a liver.  Alternatively, a microscopic view of a liverwort can suggest the microscopic view of a liver. Either way I don’t think they help much medically.  But they are top-quality botanical curiosities and they help make it all much more fun to explore the infinite world of green.  Here are some local liverworts from our “archives.”

Riccardia latifrons sporophyte

Riccardia sporophyte (spore-making generation) on surface on gametophyte

Riccardia pinguis (I think)

Riccardia pinguis

Sphaerocarpus, Riverbend Park, Jupiter, Florida

Sphaerocarpus, Riverbend Park, Jupiter, Florida


Posted by on January 16, 2015 in Pallavicinia




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