Treasure Coast Natives

Being chilly today, I did something I like to do on such days, watched the WPB Manatee Lagoon live manatee cam. As I tuned in there was a manatee unusually close to the underwater camera, presenting a view new to my experience:   a submerged live close-up of manatee skin and associated fishy business.

Seen from a little distance manatees always seem to wear a lot of algae and other tagalongs. But seeing it up close was eye-opening in two ways:

1. A lot of the algae is not green, slimy, or stringy, but rather little rusty-brownish tufts on some but not all manatees.
2. Swarms of tiny fish hover around some of the mighty beasts expressing interest  in manatee skin and what’s on it.

Now…I’m no expert on manatee dermatology, but a little Googling turned up novel fun. No need for a blog anymore!  AI is an instant blog on demand.   Replaced by the machine!?  Despite that impending complication, the brownish algal tufts perhaps-to-probably belong to one or more of three species of red algae (not red tide)  described since 2019 by biologists Karen Woodworth, D.W. Freshwater,  and colleagues  as manatee skin dwellers. The fist-known of the three is Melanothamnus maniticola. (Manticola means roughly “lives on manatees.”)

Photo by NOAA on Unsplash

As the algal discoverers pointed out, the alga and the manatee are a match made in heaven.  Although unproven, it seems the manatee may benefit from the algae as “sunscreen.”   And the algae have several adaptations to wastin’ away again in manatee-ville, especially a system of little “fingers” to cling to the rough skin.   The algae are extra-tough, which helps when attached to a submarine that brushes against other submarines, weeds, and logs.    Manatees have also “their own” species of barnacle  too, Chelonibia manati.  The barnacle cruises on its free ride trawling for detritus. Not well checked out, it probably enjoys first dibs on shedding manatee skin and other manatee-debree.

Yet another recently discovered unique manatee-rider gets in on the bounty.  The diatom (broadly speaking a type of microscopic algae) Tursiocola gracilis, discovered in 2015 by T. Frankovich and colleagues, behaves in a most-unplantlike fashion. It performs no photosynthesis. Rather, somehow it derives nutrition from dead manatee skin and/or microbial life on it.  The abundant diatoms are thought perhaps to suppress harmful microbes on the grateful manatee’s hide.

Fish cleaning manatees are pretty well known, extending to multiple species of fish, picking off algae, parasites, and shed skin.   They are presumably mostly beneficial, except for one annoyingly overzealous invasive catfish species.

In this video you can see the picky little fish. (The intense swarm toward the bottom of the video is bubbles.)

https://drive.google.com/file/d/14BmVy5l4-GFrKWpIdfkJ0yeZ-q4PZlyJ/view?usp=drive_link

Sure hope 2026 is a good year to be a manatee!

Extra things:

https://onlinelibrary.wiley.com/doi/10.1111/jpy.12912

https://www.researchgate.net/publication/340082479_For_Better_For_Worse_Manatee-Associated_Tursiocola_Bacillariophyta_Remain_Faithful_to_Their_Host

Ximenia americana

(Ximenia comes from the name of a botanical Mexican priest.)

(Don’t confuse with Spondias, which is a different  “hogplum”)

Every species in the Florida scrub came from somewhere else, or its ancestors did.   Some local scrub plants are limited to postage stamp distributions, such as 4-petal pawpaw.   By contrast, hogplum is a globalist, despite the geo-limited name  Ximenia “americana.” Its main presence is arguably in Africa, where its roots run deep in every sense, and where  I suspect it originated.   And vastly beyond.   Here is the worldwide picture from plants of the worlds online:

How does it get around so?   Birds and grounded wildlife help, but  the main mover must be the hard and buoyant fruit “pit.”  After all, the species is not only across vast swaths of hot sandy poor-soil mainland, but also on oceanic islands, mostly near the shores.   In Florida this prickly, partly parasitic, crooked shrub lives sometimes in hammocks, more often in scrub, including the  most sunbaked, forlorn, barren spots.  We’ve looked into its biology previously:

https://treasurecoastnatives.wordpress.com/2015/08/29/hog-plum/

So today let’s  go for more of the global story.    Making plumlike fruits,  good wood where wood is hard to grow, fodder, and traditional medicines, today’s species has broad and old roles in human affairs in other regions. (BTW, although the fruits serve as human food in regions with ancestral knowledge of preparation, the species produces cyanide and maybe worse,  so no sampling!)

All of today’s plant pictures by John Bradford.

There’s a lot of it across sub-Saharan Africa. In Ethiopia the shrub has declined in recent decades due to population expansion coupled with over-harvesting for the beautiful sturdy wood used for utensils,  splinter-free handles, and charcoal.  A problem there we don’t experience much in Jupiter is competition for the fruits with baboons and monkeys, although racoons eat the plums abundantly. Speaking of wildlife,   one of many reported applications is usage internally and externally against cobra venom.   Additional medicinal uses are too numerous to list here, but a sampler I found interesting include countering  constipation (mentioned often and emphatically), fleas,  leeches, leprosy, hemorrhoids, and Staph infections.  In India fragrant Ximenia wood smoke is valued for incense and fumigation.    In places, the fermented fruits are ingredients in beer, and the fruits rarely, I think, to flavor gin. In Indonesia the leaves are ground into a condiment (although I don’t see or smell why). In Tropical Asia it turns up in jellies and preserves.

The seeds are rich in stable, easily preserved oil with every use for oil you can think of, and more:  for contraception (?), for hair, for antisepsis and healing, as a lip balm, for youthful soft skin, for cooking, and as lamp fuel.   The oil has industrial value as a binder for pills.

Our little tree has garnered climate change attention.  Burkina Fasso is well endowed with Ximenia americana where it serves all the purposes noted above. A recent study showed about 62% of the land area to be proper habitat, but climate change models reduce that by 15-25% by 2070. That is important because its fruiting peak is during months when other gathered foods become scarce. A single tree can generate 50 kg of plums, creating opportunities to sell them along roads and in markets.   The year-round foliage is a mainstay for livestock herders.

Let’s return briefly to the wood. Before WWII it was an export to Japan from the Yap Islands east of the Philippines.  I think the most remarkable use for Ximenia americana comes from Fiji.  In that nation wooden stands called kali are neck “pillows” elevating the head to avoid messing up large elaborate hair styles during sleep, especially among nobility. The favorite hardwood for kali was, you guessed it, Ximenia americana.   We already learned above it is beautiful, hard,  splinter-free and fragrant characteristics.  They polished it to a glossy finish using shark skin.

In Florida, next time you stroll through the scrub, the hogplum is not a mere thorny ankle-poker with fragrant flowers and raccoon food.   It is a gnarly green museum of worldwide significance. And I’ll bet there a whole lot we don’t know about its storied history in human affairs where its plums, wood, and oil have been needed (for keeping your hairdo tidy)  for tens of thousands of years.

Are blogs past their prime?  Yes for sure, in a world of podcasts, X, streaming stuff, and laptop & desktop displacement by fancy fones and other devices.    Even so, natural history never gets old (to John and to me), so despite technology leaving us forlorn, here we go again old-school,  today about ants and plants.

Harvester ants. Big heads. Big jaws for seeds and for foes. The crowded door to the underground colony is toward the top left. By John Bradford.

In the white sandy coastal scrub native harvester ants (Pogonomyrmex badius) have some odd ways and means.   Their nests are abundant and easy to find in open sugar sand, resembling an upside pie pan with a busy central portal leading to a huge subterranean colony.  

Colony today with its black charcoal-y fence.

Around the portal is a barren “yard” scurrying with ants, the yard surrounded by a dark “fence.”   That fence is the feature attraction today.  It  is a ring of debris, much of it waste from the nest, no surprise there. The surprise is that the ring is also so loaded up with burned bits of charcoal that the overall coloration is almost black. Bits of charcoal? Yep.  

The ants seem to gather it from past fires.  WT-heck is that all about?  Nobody knows definitively, but not for lack of trying  by biologists over the years.   Several past suggestions exist, some purely speculative, some checked out.   Here’s a quick list of previously published possibilities:

1. To exclude enemies.  The “defensive perimeter” idea is obvious but flawed, especially,  “what enemies?”  The main natural enemies of Florida harvester ants are parasitic wasps.   They fly, so a fence is no D.   Also unfriendly are fire ants, but they did not evolve with harvester ants, and besides, would charcoal chunks block any kind of ant?  Maybe not physically, but perhaps as a “no trespassing” notice to encroachers even of the same species  from different colonies. The defenders have ferocious chompers, and they can sting too.  We’ll come back to the  “no trespassing” concept.

An enemy that attacks ants on the ground—after prior airborne dispersal—are ant lions, and they can lurk around harvest ant habitats.   The lions scoot across the sand to set ant traps, and a fence may discourage violating the  ant campsite.  But the ant colony is mostly subterranean and essentially immune to ant lions.   It is hard to imagine ant lions as a force to reckon with.

2. A different notion is that the black fence is a landmark ant foragers beyond the pale can see from the distance when lugging home the harvest of seeds. A homing beacon.  (Naw)

3. A third proposal is that the black charcoal, like a black car, absorbs heat to warm the nest on chilly mornings.   Trouble is, the nest can be 10 feet deep.

4. Charcoal absorbs organic compounds, perhaps including chemical signals. The resident ants could infuse the charcoal with pheromones, warning unwelcome ants to bug off.  Efforts by other people to test this have come up dry.   

https://drive.google.com/file/d/1YyNXYzAlrvX10lFF14FlGxVC0lJL9iOS/view?usp=sharing

5. A related older speculation is that the charcoal is a favorable seed bed to help stubborn seeds sprout into ant food. Investigated but never demonstrated. Undermining all explanations involving special characteristics of charcoal, non-Florida harvester ant species make similar fences but use non-absorbent pebbles instead of briquettes.  Florida harvesters in sand don’t have pebbles, so maybe the burnt bits are merely locally available substitutes. (Are harvester  ant colonies related in size, health, or abundance to charcoal availability?)   Charcoal pieces are usually sparse on scrub sand, so the investment required to gather thousands of them to the nest site must be costly!   They must also serve an important purpose.     To see if the charcoal ring “matters” to the ants, the other day  I scooped a small portion of a charcoal ring away.  Remarkably, by the following day they had repaired it fully.

John and I discussed the fence question today, and jointly have an idea to “toss into the ring.”   In all the historical speculations, there is little-to-no attention to the second function of fences: confinement.    Let’s say keeping junkyard dogs in the junkyard.    Those big-headed, heavy-jawed, biting “major” ants roaming inside the fence are scaled down junkyard dogs.   It would be a problem to junkyards and to harvester ant colonies to have the guards (and workers) wandering away willy nilly.  We suspect the fence defines the duty station for its occupants. In the video link above you can see ants wandering to the fence, and then redirecting back into the yard to remain effectively useful.

Evening-Primroses, lovely members of the big genus Oenothera with almost 100 species in North America, are well represented as mostly bright yellow wildflowers in Florida,  some in  open sandy habitats. One cosmopolitan beach species, arguably native to Florida, Beach Evening-Primrose (O. drummondii), found itself called out recently as listening for  pollinators.  Yes, listening.

Photo courtesy of Harry Rose.

Biologist Marine Veits and a group of collaborators in 2019 reported honeybee buzz and similar vibes, but not other tones, to induce increased sugar concentration in the nectar.   In their interpretation, this ability sweetens the pot  upon demand, promoting bee pollination yet conserving sugar when there are no customers.   What’s more, the petals resemble one of those parabolic microphones they use to focus birdsongs, to capture frog calls, and to eavesdrop on conversations.

It may all be just as reported and interpreted, but questions come to mind:

1. Are bees meaningful pollinators for evening-primroses?   The flowers are (actually) textbook examples of moth-pollinated blossoms, having long tubes producing nectar way down deep exclusively reached by a moth’s long proboscis.   But bees are known to visit the flowers, perhaps merely gathering pollen, as bees do.   That could result in pollination without nectar consumption.   Then again, who is to say the long tube can’t fill with sweet nectar, allowing an occasional bee sip.  

Nectar is produced at the bottom of the long skinny tube. Bee can’t reach there.

• Would a small increase in sugar content boost pollination?  Not if the bees are there just for pollen. And even if they are obtaining some nectar, it’s not been shown (pretty hard to accomplish!) that marginally raising sugar concentration leads to more pollen deposited by more bees on more stigmas.  

• In 2017 botanist Sebastian Anton and collaborators studied the floral dynamics of several evening-primrose species in Europe and found the flowers to not just release nectar into the tube, but also to suck it back in dynamically, depending on circumstances.  The nectar level waxes and wanes.  As the flowers reduce the nectar volume, the sugar concentration increases.  That is, sugar concentration increases when the flower is stashing away nectar, not dishing it out.   Does buzzing set off a flower alarm:  “Hey, non-moth invaders detected, hide the goodies!”   After all, some types of bees drill into flowers and steal nectar like mosquitoes stealing blood from my elbow.

• Yet another concern is that the flowers don’t have any identified “nervous tissue,” whatever that could be in a plant.   Absence of detection does not prove absence of some subtle signal, duh, but it doesn’t help either.  Plant cells live within extremely thin delicate membranes with their own innate molecular movements and unimaginably delicate processes.  Whether or not buzz detection is usefully adaptive, vibrating cell membranes could conceivably change cross-membrane transfer dynamics, maybe even make membranes “leaky.”   That is, could vibrational sugar leakage take place with no purpose?

Who knows?   The idea is new and fascinating and plausible, and that is how science works.  Taking another look at the same question with additional bee and flower species is joyous future grist for the mill.   The original research was in the Mediterranean. Now somebody should try in Florida.

to see more:

DOI 10.1007/s00425-017-2748-y

DOI 10.1111/ele.13331

Today the Honeycombheads (Balduina angustifolia) were bright in the scrub, blooming massively attracting a whole lot of floral visitors.  We’ve enjoyed them before: https://treasurecoastnatives.wordpress.com/2021/09/10/honeycomb-heads-have-their-very-own-bee/

Most of Florida was submerged several thousand years ago, although sandy dunes and ridges here and there were above the waves.  Those “islands” and more recently exposed dunes became our modern scrub. That poses the fascinating question of, where did all the scrub flora and fauna come from? Without a deep dive into that immense topic, suffice it to say here, some species arrived from the more-arid and scrublike southwest like Scrub Jays, some wandered southward  from points north, some floated from afar by sea (like probably Ximenia), and some evolved on the scrub from variably distributed and wandering ancestors. And so forth.   You could ponder that for a whole career.

So, ya gotta wonder how we got those flamboyant Honeycombheads, which are mostly restricted to sandy open places like scrub in Florida and nearby. And now we shall speculate wildly.  (Yes, a proper DNA-based evolutionarystudy is called for, but in the absence of that I have a license to make something up.)

What makes it fun to wonder is that there are only three species of Balduina, all of them native to the Southeastern U.S., the other two (B. atropurpurea and  B. uniflora) centered on terra firma to the north of Florida. Those two species extend together from North Carolina to the Gulf,  in Floria both limited to the northern counties.  Today’s  species, B. angustifolia, seems likely a sandy scrubby southern offshoot of the more-northern pair Balduinas.   (Interestingly btw, B. uniflora has twice as many chromosomes as the other two species.)

The two “northern” species then could have existed before South Florida emerged from its ancient submersion.   The northern species both favor wet sandy shores.   Having the same number of chromosomes as B. angustifolia, B. atropurpurea (or conceivably an extinct close relative) looks like an older mainland ancestor for B. angustifolia. That species could have split off evolving into newly forming scrubby habitats as Florida rose above the sea. Even today’s scrub is not so different from the ancestral “sandy shores,” just particularly well drained and sterile.

Polygonum polygamum

Polygonaceae

Photos today by John Bradford except the poorly focused wasp

October Flowers declares October is here.    Been too hot through the summer for a’wandering far, but today called out cooler, and the fall floral friends were pleasing: Smilax fruits looking like grapes,   “Florida Paintbrush,”  Tarflower (hey that’s not supposed to be open now!?),  and the feature attraction: October Flower.    Despite prior attention (https://treasurecoastnatives.wordpress.com/2021/08/27/october-flower-is-fun-to-watch/) ,  I can’t resist posting this white delight again.   A thing I love about October Flower is rooted in the ecology of native pollinators:

They’re hurting, especially in disturbed, polluted, urban/suburban woodsy fragments.   Depressing studies (not locally)  tend variably to reveal urban conditions to be harsh for native pollinators.    Nature lovers with suburban gardens, like me, “help the pollinators,”   which can be only partially true since pollinator richness and diversity depend on diverse factors beyond garden flowers. 

We all love honeybees, but, pity, they are invasive exotics al-bee-it with benefits.  All this being so,  I take special joy in native pollinator watching, even though the bee house in my garden is vacant.    Some native wildflowers attract native visitors like bees to honey.   October Flower is one of them, and being abundant in scrub remnants,  it brings a buzz of  “natural pollination” to a nature area near you.

I’m no wasp expert, but I can Google like a pro, and I think today’s visitor is a male “long wasp” (Myzinum sp.).    You see them as floral visitors, having a waspy kinda love for small white blossoms.   Avidly gathering pollen with their faces in the flower,  they seem uninterested in humans with cameras.   As an instant Google expert, let me tell you a fun fact—although the male can’t sting, it has a scary looking Captain Hook  false stinger, and will fake-it if bugged.   Here’s a picture from the UF Museum:

Thalia geniculata

Marantaceae

Today I took a walk on the soggy side among one of my favorite Florida tropical marvels, Alligator-Flag (Thalia geniculata).   Everyone around here knows it whether they know it or not—big roadside ditch plant with “banana” leaves and paired violet flowers aloft on wands as tall as a truck .  They have a complex snap trap mechanical pollination system that would impress an orchid.    That was all written up in this blog, holy smokes, back in 2012.

https://treasurecoastnatives.wordpress.com/category/alligator-flag/

So, after a 13-year gap, it is time for Thalia Phase II:   co-habitant insects.     They are weird and poorly known.  The identities of the today’s Thalia companion species (in addition to the Canna Skipper) are handy thanks to a helping hand from bugnet.guide.

If you go look closely at Alligator-Flag inflorescences, which requires wet feet or a boardwalk such as Wakodahatchee Wetlands or Green Cay, you’ll probably find the True Bug Ischnodemus sallei scurrying, and mating immodestly,  on the branchlets among the flowers.   Related to the chinch bugs of suburban lawn dread,  Ischnodemus sallei feeds on Thalia sap.    The species has a special affinity for Thalia, at least in South Florida.

Below is the lion’s share of the knowledge of its distribution in Florida. Notice anything?  (The non-Thalia reports of this species I’ve seen have been on plants related to Thalia outside of Florida.)

And here is a tidbit from UF entomologist Dr. Susan Halbert:

Don’t want to bore you by getting too far into the weeds.   I just fancy a special relationship between one of our coolest wildflowers and its own bugs, even if they suck.    The Ischnodemus sallei abundance on Thalia is so bountiful locally,  I wonder if the insects disperse with floating plant parts of this shore-dweller.

Also abundant on Thalia,  and also poorly known, is a bigger, showier species of leaf-footed bug, Namacus annulicornis.    If you bother Ischnodemus sallei it disappears furtively into the spaces between the leaf sheaths and the stem. By contrast, when bugged, Namacus flies off in a huff, and seems to emit a stinkum on the way..  

Namacus

This bug appears to have Alligator-Flag as its sole host according to R. Barananowski and  J. Slater in their 1986 account in the Arthropods of Florida:

Eggs

Those bright red nymphs (below) look so much like Assassin Bug nymphs, I wonder if there is mimicry of some sort.

Funny how, when a flower has an “oh-my” pollination system, its more mundane aspects can  go overlooked.