The
Palmetto
Florida Szechuan Pepper l Red Mangrove Mysteries l Carlyle Luer
Florida Native Plant Society Annual Conference
University of North Florida, May 14-17, 2020
10 reasons not to miss the 2020 FNPS Annual Conference in Jacksonville!
Full-time Students
Are you a full-time student? Many FNPS chapters are helping to sponsor student attendance for socials, dinners and hotel accommodations. Contact your local chapter for more information.
Chapter Conference Brochure
1. Presentations on a wide range of topics. The conference features 33 speakers, all types of talks and workshops, plus the new Southeastern Native Plant Societies track. Visit https://www.fnps.org/conference/2020 for details.
2. A huge, multi-vendor plant sale where you can purchase native plants.
3. Network with people working around the state on behalf of native plants and native plant communities.
4. More than 20 field trips. There’s something for everyone, from education centers to hiking, kayaking and more!
5. Discover FNPS projects that conserve native plants throughout the state.
6. Opportunities to learn more about why native plants are important and how you can help save them.
7. Techniques to make your landscape and community more resilient by using real Florida natives.
8. Learn how to invite birds and pollinators to your yard and community.
9. Jacksonville is home to more parks than any city in the country, and amazing natural areas are located nearby.
10. Activities get you in touch with other native plant enthusiasts. Meet up at socials, dinners, a plant ID contest, the vendor area or the silent auction.
A conference brochure chapters can use to promote the conference will be available in January. The brochure can be downloaded from the FNPS website’s conference pages. Printed brochures will be handed out at the February in-person meeting. https://www.fnps.org/conference/2020
The Quarterly Journal of the Florida Native Plant Society
Palmetto
Staff
Juliet Rynear ........................Executive Director
Valerie Anderson ...................Director of Communications and Programming
Board of Directors
Officers
President ..............................Susan Carr
President Elect ......................Bonnie Basham
Vice President, Administration ....David Martin
Vice President, Finance .........Jim Erwin
Treasurer ..............................Bonnie Basham
Secretary ..............................Jacqueline Rolly
Committee Chairs
Communications ...................Shirley Denton
Conference ...........................Marlene Rodak
Conservation ........................Todd Angel
Education .............................Wendy Poag
Land Management Partners ....Grace Howell
Landscape ............................Ronald Blair
Policy & Legislation ...............Eugene Kelly
Science ................................Paul Schmalzer
Council of Chapters
Chair.....................................Kara Driscoll
Vice Chair .............................Gail Parsons
Secretary ..............................Athena Philips
Directors-at-Large
Carole McKay
Carol Sullivan
To contact board members:
Visit www.fnps.org or write care of: FNPS PO Box 278, Melbourne, FL 32902-0278
Society Services
Administrative Services ........Cammie Donaldson Editor, Palmetto .....................Marjorie Shropshire Webmaster ...........................Paul Rebmann
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Features
4 Florida Szechuan Pepper: A Financial Opportunity
Fruit capsule valves from various Zanthoxylum species are used as a spice in countries spanning the globe. Could the native Florida species Zanthoxylum clava-herculis serve as a tasty alternative? Article by Francis E. “Jack” Putz and Nidhi Patel.
8 Red Mangroves, International Trees of Mystery
Red mangroves (Rhizophora mangle) are extreme in appearance and in lifestyle, sporting dramatic buttress roots and dangling embryos resembling oversized green beans. These oddball trees remain mysterious despite frequent study prompted by their curious extremes and worldwide distribution. Article by George Rogers and John Bradford.
12 Carlyle Luer – 1922-2019
The chance discovery of Carlyle Luer’s book
The Native Orchids of Florida led Roger Hammer to what would become an obsession – exploring every conceivable habitat, simply to find and photograph the wealth of native orchids Florida has to offer.
Article by Roger L. Hammer.
Palmetto
Editor: Marjorie Shropshire Visual Key Creative, Inc. pucpuggy@bellsouth.net l (772) 285-4286
(ISSN 0276-4164) Copyright 2020, Florida Native Plant Society, all rights reserved. No part of the contents of this magazine may be reproduced by any means without written consent of the editor. Palmetto is published four times a year by the Florida Native Plant Society (FNPS) as a benefit to members. The observations and opinions expressed in attributed columns and articles are those of the respective authors and should not be interpreted as representing the official views of the Florida Native Plant Society or the editor, except where otherwise stated.
Editorial Content
We welcome articles on native plant species and related conservation topics, as well as high-quality botanical illustrations and photographs. Contact the editor for guidelines, deadlines and other information.
ON THE COVER: The rare orchid Pelexia adnata, photographed in Fakahatchee Strand by Roger L. Hammer.
Florida Szechuan Pepper: A Financial Opportunity
By Francis E. “Jack” Putz and Nidhi Patel, University of Florida
Now that we’ve decided to call off the planned IPO and forego the profits from commercializing our discovery of a Floridian source of Szechuan pepper, we’re ready to describe an incredible opportunity for farmers in the South to cash in on a native plant while reducing America’s trade imbalance with China. The source is Zanthoxylum clava-herculis, locally known as Hercules club, prickly ash, tickletongue, and toothache tree, a native American species with untapped commercial potential. Our research revealed that capsule valves from the fruits of this familiar hedgerow species provide a suitable substitute for Szechuan pepper imported from China and sold in this country for $9.99 per ounce. With the citrus industry crippled by Huanglongbing disease (i.e., citrus greening), Florida Szechuan Pepper might be just the ticket for farmers seeking financial solvency. We decided against cashing in on our discovery when we confronted the bureaucratic complications of patent registry and profit-sharing with our university as well as creeping suspicions about various nefarious political shenanigans related to this wonder-crop.
Far left: Zanthoxylum clava-herculis – photos by Shirley Denton.
This page: Zanthoxylum clava-herculis spines – photos by Shirley Denton. Giant swallowtail butterfly and giant swallowtail butterfly egg – photos by John Lampkin. Larva of the giant swallowtail on Zanthoxylum clava-herculis – photo by Marc Minno.
Jack’s interest in the genus Zanthoxylum dates back to when he discovered that vine infestations were significantly less likely on species of trees with trunks armed with spines, prickles, or thorns than on otherwise similar trees with spineless bark; Z. panamensis was one of those armed and vine-free species. Spinescence is often considered a legacy of the need for defense against browsing by big beasts such as the ground sloths and mastodons that were common before the mega-faunal extinction at the dawn of the Homogeocene, but his data suggested an alternative to the “Anachronistic Armaments” hypothesis. Diligent young scientist that he was, rather than risk making an incorrect inference of a process from a pattern, he set about to test his idea experimentally.
To test the hypothesis that vines that twine (predominantly counterclockwise) around armed tree trunks are sawn off when the trees sway in the breeze, he planted a fast-growing vine that twines (Dioclea megacarpa) at the bases of fifty Zanthoxylum saplings and fifty smooth-trunked saplings. Saplings of both sorts were common around the complex of laboratory and residence buildings on Barro Colorado Island (BCI) in the Canal Zone (now Panama) where he then resided. Once the vines ascended the saplings, he commenced the experimental treatment, which involved daily sessions of sapling swaying to mimic the effects of wind.
Jack was quickly bored by sapling swaying so he automated the process by tying saplings to nearby doorknobs so that when the doors opened and closed, the saplings were jostled. The experimental design involved some path crossing with strings and the laboratory complex did appear just a bit like a giant spider web, but automation worked perfectly. The treatments were terminated somewhat prematurely in response to vociferous complaints from other BCI residents about having to step over the taught strings.
After each vine-twined sapling was jostled back and forth hundreds of times, not a single vine stem was damaged. That counter-intuitive finding still perplexes Jack 40 years later, but he is convinced that something was askew with the experimental design and remains convinced about the brilliance of this natural history insight.
While vine sawing still seems like one of their roles, trunk spine/prickle/thorn multi-functionality is suggested by their increased densities and sizes on resprouted trees, which support the anti-herbivore defense hypothesis. Be that as it may, spines provide no defense against leaf miners and the caterpillars of the glorious giant swallowtail butterfly (Papilio cresphontes). Similarly, the white-tailed deer that nibble the young leaves are not spine-deterred. Fortunately (or not), given recent advances in molecular genetics, it should soon be possible to test the effects of toothache tree prickles on formerly extinct mammoths, glyptodonts, and shovel-tusked gomphotheres.
Our discovery of the commercial potential of capsule valves of our own Zanthoxylum started when Nidhi, then a dental school-bound undergraduate, inquired about research opportunities in Jack’s lab. From his list of potential projects,
she selected a sketchily described one about toothache tree, little suspecting where that selection would lead.
Nidhi’s dive into the literature soon revealed that fruit capsule valves from various species of Zanthoxylum are used as a spice in countries spanning the globe. Szechuan pepper from the Chinese species Z. simulans (or Z. fagara, Z. piperitum, or Z. bungeanum) is the best known commercially, but other species contribute to the cuisines of Nepal and Tibet ( Z. alatum), India ( Z. rhetsa), Korea ( Z. schinifolium), Japan ( Z. piperitum ‘sansho’ ), and Indonesia ( Z. acanthopodium). Zanthoxylum capsules are also reportedly employed by cooks in Africa, and one Mexican chef reported that in addition to the pungent flavor, she appreciates that mouth-numbing enhances the taste of chilies and other spices.
Zanthoxylum bark, leaves, and fruit capsules pack a onetwo punch of flavor and tongue-numbing. As a member of the Rutaceae, the family that includes oranges, grapefruits, and kumquats, the citrusy flavors of limonene, citronellal, methyl cinnamate, and cineol are expected, but the numbing property is unique to the genus. That anesthetic response is due to alkamides derived from polyunsaturated carboxylic acids, most likely tetradecapentaenoic acid with isobutylamin, also known as hydroxy sanshool. Sanshool apparently acts like some other anesthetics by activating sensory neurons and inhibiting background potassium conductance.
The defining encounter of the collaboration between junior student and senior professor occurred a fortnight after Nidhi started her on-line research. The two met in person for the first time when they sat across from each other in Jack’s lab; between them on the table was a bowl of freshly collected Zanthoxylum clava-herculis capsule valves. After chatting for a few minutes about classes and shared interests, Jack asked Nidhi point-blank, “Are you going to eat one?”
With no hint of alarm about the question, Nidhi slowly looked down at the bowl, looked up into Jack’s face, and replied, “Are you?”
Jack hid his amusement about her pluck, nodded with the solemnity fitting for the occasion, and we both selected slivers of capsule valve. After deep breaths, we popped them into our mouths and started to chew, looking into each other’s faces
Above: Zanthoxylum clava-herculis – photo by Shirley Denton.
all the while. As we masticated, the pungent lemony flavor was soon overwhelmed by a remarkably strong numbing of tongue and lips. We withstood the sensation for as long as possible and then both bolted for the sink where we jostled for access to the water.
Once the buzz diminished, we sat back down to consider possible research projects about this remarkable spice. Nidhi’s first comment was that she’d tasted Szechuan pepper before, but by another name and in a dish cooked by her Gujarati mother.
Given that the Florida species was not yet known to culinary science, we decided to compare it with store-bought Szechuan pepper on the basis of the citrus flavor and numbing intensity. For experimental subjects we recruited family members, including Nidhi’s Delta Phi Omega sisters. We asked our subjects to rate on five-point scales the citrus flavor and numbing effect of powdered Florida and store-bought Chinese Szechuan pepper. We carried out the same comparison but with a noodle dish Nidhi prepared with Chinese five-spice seasoning (cinnamon, cloves, star anise, fennel seeds, and Szechuan pepper) with either Chinese or Floridian Zanthoxylum pepper. Our results revealed that in regards to both flavor and anesthetic effect, Florida Szechuan came in close second to the Chinese import and was uniformly endorsed as an excellent spice.
Markets for Florida Szechuan Pepper will undoubtedly soar when it’s realized that it can be readily substituted for the imported product in recipes for a wide variety of dishes. Increasingly, consumers care about the sources of their food, so marketing efforts should consider taking the terroir tack. The huge demand from beer brewers for pepper remains to be tapped; they want locally grown hops, so when Florida Szechuan Pepper becomes commercially available, they will buy it in bulk. The novelty ice cream market should also be explored. We initially thought that applying the name “pepper” to this product would confuse consumers, but given growing snobbery about white and black pepper from Piper nigrum (Piperaceae), Brazilian pepper from Schinus terebinthifolius (Anacardiaceae), and chili pepper from Capsicum spp. (Solanaceae), perhaps a rutaceous pepper will have market appeal. Florida Szechuan Pepper oil and tabasco-like sauce might also find ready markets among sophisticated consumers with refined palates.
Even if Florida-style Szechuan pepper isn’t a market sensation for food and people don’t incorporate its delicious young leaves into their diets, the species should definitely be included in our pharmacopeia. In addition to the hydroxyl sanshools that cause tongues to tingle, toothache trees also produce a stunning array of flavonoids, terpene, benzophenthridine, pyranoquinoline, quaternary isoquinoline, and aporphyrine alkaloids, as well as several lignans. Which of these compounds is effective against what ailments is not yet entirely clear, but Chinese pharmacists prescribe Zanthoxylum extracts to fuel the body’s “middle burner,” whose energies power immune responses and aid digestion.
We believe we are the first researchers to discover the commercial potential of Zanthoxylum clava-herculis capsules as a substitute for imported Szechuan pepper but are nevertheless
concerned that other forces may be at play. What tipped us off was that from 1968 to 2005, the United States Food and Drug Administration banned imports of Szechuan pepper on the pretext that it might transmit Xanthomonas axonopodis bacteria, the cause of citrus canker. Toothache tree is a distant cousin of citrus in the same botanical family and it may, indeed, carry that dreaded disease. But import bans and tariffs are also a good way to protect fledgling industries. A familiar example of this sort of protectionist action by the government were the steep tariffs on imported tung oil in the 1950s and ’60s that kept local tung growers in business long after the industry was no longer viable. But when Florida’s Institute of Food and Agricultural Sciences representatives were asked about commercial interests in Florida Szechuan Pepper, they acted as if they’d never heard of the idea. Similarly, when a senior administrator in the Trump Administration was asked the same question, he too pleaded ignorance.
Would-be growers of Florida Szechuan Pepper will be pleased to learn that toothache trees are drought-hearty, require little fertilization, start reproducing when only 2 years old, and take to pruning like the best of bonsais. Jack planted less than 5 acres on 10-foot centers and is already enjoying the fruits of his labor. He also discovered that if a neighbor’s controlled burn escapes, the top-killed trees resprout readily from their prominent lignotuber. The sprouts are prickly, but quickly regain reproductive status so you’re back in the money almost overnight.
Realization of the market potential of Florida Szechuan Pepper will benefit from a marketing campaign, which might start with a name change. The services of the folks who describe fine wines should be employed so that the spice’s pungent bouquet, opening notes of citrus, and the way it closes with a buzzing finish are all stressed.
References and Further Reading
Adesina, S.K. 2005. The Nigerian Zanthoxylum; chemical and biological values. African Journal of Traditional, Complementary and Alternative Medicines 2: 282 – 301. Yang, X. 2008. Aroma constituents and alkylamides of red and green huajiao (Zanthoxylum bungeanum and Zanthoxylum schinifolium). J. Agric. Food Chem. 56: 1689–1696.
About the Authors
Francis E. “Jack” Putz teaches botany, ecology, and tropical forestry at the University of Florida and conducts research focused on nature conservation. He is the author of Finding Home in the Sandy Lands of the South, a volume of Florida-based natural history essays, Yaupon Wins: An Ethnobotanical Novella, and, under the nom de plume of Juan Camilo Moro, the steamy jungle novel Borneo Dammed: A Very Family Affair, all available from Amazon and Kindle.
Nidhi Patel graduated from the University of Florida where she was an active member of the South Asian Sorority Sigma Sigma Rho. She is currently completing a master’s degree in medical sciences at Lake Erie College of Osteopathic Medicine (LECOM) where she will attend dental school.
NOTE: Zanthoxylum clava-herculis contains potentially toxic alkaloids and potential harmful effects on humans are unknown. The Florida Native Plant Society does not endorse or condone its use for human consumption, but merely provides information about Florida’s native plants to the public.
Red Mangroves, International Trees of Mystery
By George Rogers and John Bradford
Red mangroves (Rhizophora mangle) are extreme in appearance and in lifestyle, inhabiting tidal swamps with their dramatic buttress roots and with dangling embryos resembling oversized green beans. These oddball trees remain mysterious despite frequent study prompted by their curious extremes and worldwide distribution. The more you learn, the more mysterious they become.
Start with life wading in the brine. Surprisingly, red mangroves can grow in freshwater. So why banishment to the tidal fringe? Two reasons come to mind. First, the trees are not great competitors, so they thrive where the competition can’t – in nasty oxygen-starved tidal mud.
The second reason for restriction to tidal zones is that the water-dispersed embryos are too big and are shaped badly for dispersal inland onto shallow mudflats (Rabinowitz, 1978). They can, however, survive a year floating in the sea with their upper tips bobbing above the water line (Boufford & Gillespie, 2017).
Botanists A. Gil and P. Tomlinson documented aeration of the deep-set roots. The business ends of the arched roots periodically sink under tidal flooding, with the deeper portions permanently in suffocating mud. Down there the roots have open air passages, which become smaller higher in the root. To ventilate those passages, the portion of the root above the mud has large white vents called lenticels filled with loose corky material. Rising tides choke off the lenticels temporarily, decreasing the pressure within the air passages. Then as the
tide drops, the diminished internal pressure sucks air in through the lenticels, literally a breath of fresh air.
The leaves bring in air too, not by sucking but rather by solar-powered pumping. Flip a leaf over and see freckles called cork-warts beneath. Those are intake valves for a sun-powered pressure system forcing air downward into the tree from the foliage (Evans & Bromberg, 2010). We have seen the base of a leafy twig connected to a sensitive digital gauge register a positive pressure fluctuating with passing clouds and sun.
Roots descending from the branches elongate rapidly before arriving at the water level. We have measured as much as 3/4 inch a week, suggesting a measure to compare mangrove vigor under varied conditions. The dangling root tips often die in midair, apparently to the benefit of the tree. Just behind the dead tip, a cluster of new roots branch forth and splay out like the legs of a tripod. That way a single root emerging from a tree limb multiplies into three or more branch roots entering the mud.
Different mangrove species handle salt differently. Black mangroves secrete salt onto the crusty leaf surface. White mangroves mostly sequester it within throwaway leaf blades. As Kim and collaborators documented, red mangroves discourage salt entry at the root to begin with, at the cost of losing the protective foliar salinity the other two local mangrove species enjoy. Consequently, red mangrove leaves suffer the most fungal and insect damage.
The large dangling embryos, often dubbed “propagules,” grow on the parent tree from small fruits surrounding the
Left to right: Red mangrove prop roots. The corky lenticels at the waterline are breathing pores – photos by John Bradford.
attachment-ends of the embryos. As a point of clarity, a propagule is a general term for any unit that propagates a new plant. What drops and floats away is the bottom portion of the bare embryo, leaving its uppermost components behind in the fruit on the tree.
Normal non-mangrove plants place embryos inside seeds and seeds within fruits. Their seeds store food called endosperm for the embryo. In red mangroves, however, the endosperm has a unique specialization. Mangrove endosperm becomes a conduit for the parent plant to pump nutrients into its enormous offspring. That huge embryo growing for several months needs far more nutrition than what a relatively small seed could store.
Why would a mangrove disperse its young as bare embryos rather than as fruits and seeds like other plants? There must be a good reason because the unrelated black mangrove does it too. Floating in the sea, the embryos do not need protection from drying, herbivores, or the other hazards of life on land. The naked embryos in the ocean are reminiscent of “naked” fish and amphibian eggs in the sea without the protective shells, food reserves, and membranes of land-bound reptiles and birds. The bare green embryos seem to manufacture
photosynthetically on a long sea voyage rather than rely on stored reserves, although this untested supposition needs verification. Upon lodging in mud, the naked embryos can continue growth with no further ado.
The flowers are paired on a Y-shaped stalk with a flower at each tip of the Y. Within several days after opening, there is a large drop-off of aging flowers so that even the youngest fruits are mostly single, one member of each twin pair aborting. In some pairs both twins survive, and others have both abort. In our survey of 157 flowers there were on average 2.04 young flowers per stalk (a few stalks have 3 flowers). A survey of 193 young fruits, by contrast, gave an average of just 1.3 fruits/stalk revealing a substantial decrease.
How red mangroves achieve pollination is much-discussed yet remains unsettled. Peer-reviewed scientific publications contradict each other with respect to the relative importance of insect-pollination, versus wind-pollination, versus selfpollination. Pollination is the arrival of “male” pollen grains onto the flower’s “female” pollen-receptive stigma to complete the sexual cycle, causing the flower to form an embryo and fruit. With exceptions, no pollination equals no fruit, no seed,
Left to right: Cork-warts on the underside of the leaf allow air intake into the plant's solar pressure pump. The long dangling “beans” are embryos. The broadened tan cap at the top of each is the fruit from which the embryo has sprouted – photos by John Bradford.
Left to right: Insect damage and fungal damage to foliage. Mutant “albino” embryos fail to form green chlorophyll, resulting in reddish or jaundiced coloration – photos by John Bradford.
Insect-Pollination
Whether insects are important pollinators is a matter of disagreement. On the negative side, a study in Brazil found that flowers with insects excluded experienced no diminishment in fruit initiation (Menezes et al). Pointing in the same direction, multiple observers (such as Tomlinson 1994) have noted scarcity in apparent insect-visitation in certain study areas.
But then again, there is conflicting evidence. Insectvisitation to red mangroves is documented. Red mangrove flowers have all the usual attributes of insect-pollination. They are large, fleshy, fragrant, and reportedly nectar-producing. Sánchez-Núñez & Mancera-Pineda in 2012 found hoverflies to be “highly effective pollinators” in a Caribbean study area. Beekeepers attribute red mangrove with contributing to honey.
Wind-Pollination
Wind has received widespread acceptance as the main or exclusive pollination despite the evidence being mostly circumstantial (Tomlinson et al. 1979). Evidence for wind pollination includes that red mangroves live in windy places, that the flowers have separate male and female phases, that pollen is abundant, and that Nadia & Machado (2014) showed reduced fruit initiation after covering flowers with wind-proof bags.
There are problems with getting carried away with wind. Fruit initiation occurs in situations where flowers are so few and isolated that significant wind-blown pollen seems highly unlikely. Late-season flowers along Jones Creek in Jupiter, Florida, made fruits in autumn 2019 with almost no other flowers nearby. The Brazilian bagged-flower experiment did not prevent reproduction altogether, and bags covering flowers likely impair floral functions, including the “assists” to selfpollination listed below.
Nobody has shown wind-pollination to happen, and a verdict of exclusive wind-pollination fails to consider compelling genetic evidence for self-pollination. Although with little hard evidence beyond many hours among the trees, we suspect wind to be of minor importance in their pollination, except perhaps within individual flowers.
Self-Pollination
Here we use the term self-pollination chiefly to refer to pollen transfer within individual flowers, although from flower to flower on the same tree would qualify. Self-pollination is common in the plant world and is the ultimate form of inbreeding. The best evidence of inbreeding (be it heart defects in Florida panthers or the Habsburg lip in the royal family) is the appearance of otherwise rare or unknown mutations. This is true of red mangrove embryos (see photo on page 9). Mutant “albino” embryos fail to form green chlorophyll, resulting in reddish or jaundiced coloration (Handler & Teas). Several studies have used the ratios of albino embryos vs. normal ones on a parent tree to estimate the percentage of self-pollination under different circumstances, with results ranging from predominant selfing (Lowenfeld & Klekowski) to substantially less. A 2018 genetic study by Francisco et al. at one site in Brazil and not based on albino embryos failed to reveal much self-pollinated inbreeding. In short, self-pollination almost certainly happens although variably and mixed with other pollination.
The reported (by Nadia & Machado) time gap between the pollen-producing male and the female phase with receptive stigma complicates self-pollination although does not rule it out. Pollen is shed in the bud or as the blossom opens on day 1. According to Nadia & Machado and consistent with our observations, the stigma becomes receptive on or near day 3. So then, speaking very roughly, “day 2” is the time gap between pollen release and female receptivity to it. How could the self-pollinated flower bridge that gap? There are plausible possibilities. One possibility is patient pollen. Pollen released on day 1 persists on the stigmas, apparently “waiting” patiently for the day-3-ish receptive phase. Flowers over 2 days old often have pollen stuck firmly to the stigma and sometimes visibly germinated upon microscopic examination.
A second potential bridge across the time gap is the wool on the inner faces of the petals. Pollen released on day 1 catches abundantly in the wool. During day 1, 2, or 3 pollen could move from the wool to the stigma by means of simple physical touching, by rain, or by wind banging the flowers, foliage, and
Left to right: Red mangrove flower phases. Phase 1: a first-day flower in male phase with abundant pollen; wool on the petals is conspicuous. Phase 2: stamens and petals are deteriorating. Phase 3: the flower is over a week old, with fruit beginning to form at the center – photos by John Bradford.
embryos around, bumping the wool and stigmas into contact, or by mites and ants.
The blossoms host mites who carry pollen on their bodies and who scurry all over the stigmas, although we find the mites dwindle in numbers after day 1. Beyond moving pollen within flowers, mites could carry pollen to different flowers by blowing in the wind, by washing to lower branches in rain, or by riding on birds or insects. Mite biologist Dr. Hans Klompen at Ohio State University identified mites from flowers we collected. These local mites are a potentially undescribed species belonging to the genus Hattena. This genus has additional species reported from Rhizophora, and its species ride in the nares of birds’ beaks, at least in Australia. Hattena mites have also been recorded hitchhiking on bees and ants. Our mites are most like Hattena incisa, a species known only from stilted mangrove (Rhizophora stylosa) on an island near Australia. By the way, hoverflies, noted above as red mangrove pollinators, sometimes include mites in their broad diets. Ants likewise commonly inhabit the flowers seeking nectar, or pollen, or mites? They could move pollen or even mites around.
Cloning
Cloning without pollination is plausible. Many plants can make seeds and embryos asexually without pollen. A salient point of evidence against pervasive cloning is that the albino embryos require self-pollination. Moreover, we have made numerous floral dissections and found no evidence of cloning. Although cloning can’t be ruled out completely, it is not a prime suspect.
There may be no single pollinator for such a widespread species. Collectively the evidence points to a dynamic mix depending on place and circumstances. There may be tropical habitats where “the right” insects are key players, and there may be colonization of new places bereft of the original insect pollinators. Self-pollination, even if not 100%, would allow pioneer individuals to establish in marginal lands like Florida without insect assistance. Despite our doubts, limited windpollination is not completely off the table.
To end the story, a quick summary. We have a tree inhabiting the most extreme of habitats where it does not need to grow. It has a complex aeration system featuring air-pumping leaves and air-sucking roots. Pollination features different systems dominant in different places, with Florida being geographically marginal and perhaps far from the original insect pollinators. Self-pollination is probably more relatively important here than
in some other regions. Mites move pollen around. The mites most like our locals live near Australia. Pollen-carrying mites can probably relocate on birds and bugs. While other plants disperse by means of fruits and seeds, red mangrove minimizes those phases and drops a big bare embryo into the tidal wash, a practice mirrored by the unrelated black mangrove. The saltresistant embryo floats away with its tip above water, where it can survive at least a year to colonize a new beach. There it can reproduce all alone using self-pollination, giving us the most widely distributed tree around the globe.
References
Alejandro Sánchez-Núñez, D., and J. Ernesto Mancera-Pineda. 2012. Pollination and fruit set in the main neotropical mangrove species from the Southwestern Caribbean. Aquatic Botany 103: 60-65.
Boufford, D., and L. Gillespie. Rhizophoraceae. 2017. Flora North America. Vol. 12. Accessed at www.efloras.org, 2019.
Evans, L., and Bromberg, A. 2010. Characterization of cork warts and aerenchyma in leaves of Rhizophora mangle and Rhizophora racemosa. Jour. Torrey Bot. Soc. 137:30-38.
Francisco, P. and numerous coauthors. 2018. Genetic diversity and mating system of Rhizophora mangle L.) (Rhizophoraceae) in northern Brazil revealed by microsatellite analysis. Cerne 24: 1-12.
Gil, A., and P. Tomlinson. 1977. Studies on the growth of red mangrove (Rhizophora mangle L.) 4. The adult root system. Biotropica 9: 145-155.
Guppy, H. B. 1906. Observations of a Naturalist in the Pacific Between 1896 and 1899: Vanua Levu, Fiji, and Plant Dispersal. MacMillan, London. [Extensive observations on mangroves, first suggestion of self-pollination.]
Handler, S. H., and H. J. Teas. 1983. Inheritance of albinism in the red mangrove, Rhizophora mangle L. P. 117-121 in H. J. Teas, editor, Tasks for Vegetation Science. Junk. The Hague.
Kim, K., E. Seo, S. Chang, T. Park, and S. Lee. 2016. Novel water filtration of saline water in outermost layer of mangrove roots. Scientific Reports. 6: 20426. Online.
Lowenfeld, R., and E.J. Klekowski, Jr. 1992. Mangrove genetics. I. Mating system and mutation rates of Rhizophora mangle in Florida and San Salvador Island, Bahamas. Int. Jour. Plant Sci. 153: 394-399.
Mehlig, U. 2006. Phenology of the red mangrove, Rhizophora mangle L., in the Caete Estuary, equatorial Brazil. Aquatic Bot. 84: 158-164.
Menezes, M. P. M. de., D. de Oliviera, and C. F. de Mello. 1997. Pollination of red mangrove, Rhizophora mangle, in northern Brazil. Acta Hortic. 437: 57.
Nadia, T. L., and I. Machado. 2014. Wind pollination and propagule formation in Rhizophora mangle L., (Rhizophoraceae): resource or pollen limitation? An. Acad. Bras. Ci. 86: 229-238.
Rabinowitz, D. 1978. Dispersal properties of mangrove propagules. Biotropica 10: 47-57.
Tomlinson, P. B. 1994. The botany of mangroves. Cambridge Univ. Press. Cambridge. Tomlinson, P.B., B.R. Primack, and J. Bunt. 1979. Preliminary observations in floral biology Rhizophoraceae. Biotropica 11: 256-277.
About the Authors
John Bradford is an avid naturalist, botanist, and photographer living in Jensen Beach, Florida. He is coauthor of the website floridagrasses.org and the Guidebook to the Native Plants of Florida's Treasure Coast. He and George Rogers have been collaborating on green projects for 15 years.
George Rogers is director of the horticulture program at Palm Beach State College, and lives in Jupiter, Florida. He is interested in plants with unusual pollination systems.
Hattena mite from a red mangrove flower. Pollen grains cling to the mite – photo by George Rogers.
Carlyle Luer
(August 23, 1922 – November 9, 2019)
In 1972 a most remarkable book was published, titled The Native Orchids of Florida, by Carlyle A. Luer. Even though I grew up in Cocoa Beach, I was completely unaware that there were more than 100 species of wild orchids in Florida. After a 1965 to 1968 stint in the Army as a tank gunner, ship winch operator, education specialist, and recruiter, I moved to Miami-Dade County near Homestead to take a job with the University of Miami. I worked on a research shrimp farm at the Turkey Point Nuclear Power Plant along Biscayne Bay, where we raised shrimp from eggs to adults to see how economically feasible it was to farm shrimp commercially.
Although I was living from paycheck to paycheck back then, when I first saw Luer’s book at the Fairchild Tropical Botanic Garden gift shop, I was so intrigued that I forked out $25 and bought a copy. Thus, began what would become an obsession, traveling all over the state and exploring every conceivable habitat, simply to find and photograph the wealth of native orchids Florida had to offer. What made this obsession easier was that for each photograph in Luer’s book, he recorded the date it was taken and the county. I would locate the proper habitat by looking for state parks or other preserves within the appropriate county, and then go there during the month when I knew the orchid would be in flower. It almost felt like cheating.
Carlyle Luer was born in Alton, Illinois, and graduated with a Doctor of Medicine degree from Washington University School of Medicine, a private research university in St. Louis, Missouri. In 1946 he set up a practice as a general surgeon in Sarasota, Florida, where he lived for the next 73 years. Upon retirement, he took up the study of orchids full time and not only helped establish the Marie Selby Botanical Gardens in Sarasota, he became the first editor of their research journal, Selbyana
I first met Carlyle at his waterfront home in 1974, just two years after the publication of his book on Florida orchids, and was able to chat with him about a few species of native orchids I had been looking for without success. One was a saprophytic, terrestrial species called Hexalectris spicata. I remember him getting up and saying “follow me,” so
Article and photos by Roger L. Hammer
Photos, clockwise from left: Ghost orchid (Dendrophylax lindenii); Lepanthopsis melanantha; Hexalectris spicata.
we walked over to a small oak hammock on his property and there was a colony of Hexalectris spicata in full bloom! Okay, that was definitely cheating!
That was the same year when I first started to explore the Fakahatchee Swamp in Collier County, where 50 of Florida’s native and naturalized orchids have been recorded. This was also the year when the Fakahatchee Swamp officially became the largest state park in Florida, encompassing more than 85,000 acres, and is now officially called the Fakahatchee Strand Preserve State Park. It is worth saying that my first trip out there alone was intimidating because I was faced with miles of trackless swamp and only a small compass to find my way around. But, countless trips later, and armed with a map that I drew after photographing the swamp from the air to find hidden lakes and sloughs in the interior, I found myself wading miles into the most remote regions of the swamp, sleeping in a jungle hammock stretched between trees above the water, and then wading even deeper into the swamp the following day. Then, in September 1975, I waded the entire length of the swamp, emerging at Alligator Alley (Interstate 75) five days later, but recording 30 species of orchids on that single trip. I can attest that when you’ve spent five days in a dismal swamp wearing the same clothes, it is not easy to catch rides while hitchhiking, and I may have been the very first Skunk Ape sighting in Florida! Finally, I was able to hop on the back of a stake-body truck that was hauling caged chickens to Everglades
City, so I hopped off at the entrance to Janes Scenic Drive and walked the five miles back to my 1965 VW van, still parked where I’d entered the swamp five days earlier.
One orchid that I found on that trip was Lepanthopsis melanantha, a tiny and extraordinarily rare orchid that had eluded me after several years of intense searches. Luer wrote that it was first discovered in Florida in 1931, and I read his book so many times I memorized his exact words – “Since that time it has been seen on only relatively few occasions. This is easily appreciated by anyone who has tried to find it. Not only is it diminutive and secretive in its habitat but it is also quite uncommon in the most inaccessible recesses of the swamp.” After many years, and untold numbers of trips into those inaccessible recesses, almost always solo, I have found this quaint little orchid only seven times (see photo on page 13).
Just two months later, in December 1975, I decided to explore the west side of Janes Scenic Drive to photograph a rare orchid called Prosthechea pygmaea that I had seen several times before, but not in flower. After that mission was accomplished, I decided to follow that deep slough to the south, in uncharted territory for me, and after wading about a half-mile, I came upon an open slough filled with pop ash (Fraxinus caroliniana) and bald cypress (Taxodium distichum) trees, and one of the pop ash trees had orchids dangling from its trunk and branches. I knew every orchid in Luer’s book from memory, and this one didn’t match any of them. I took photos and tried to memorize
Photos, from left: Maxillaria parviflora; Pelexia adnata
the location so I would be able to return, and then in April 1976 I took Carlyle Luer out to the station but, since the plants were not in flower, he collected a piece of one of the plants and flowered it the following September at Marie Selby Botanical Gardens. It was a new species for Florida, known at the time as Maxillaria conferta, but the name was later changed to Maxillaria parviflora and then to Camaridium vestitum. And now it’s back to being Maxillaria parviflora!
As fate would have it, in November 1977, I was exploring Fuchs Hammock, a Miami-Dade County preserve just west of Homestead. I had started working at Castellow Hammock Nature Center for the Miami-Dade County Parks Department just eight months earlier, and wanted to check out this hammock because I knew it harbored several species of orchids. Part of the hammock was being invaded by an exotic aroid called Syngonium podophyllum, which formed a dense groundcover in some areas. While slowly walking through a patch of this invasive plant, I noticed some peculiar leaves that were covered with white spots. After a close inspection, I realized it was an orchid, and the plants looked superficially like a species called the spurred neottia (Eltroplectris calcarata) but I’d never noticed spots on its leaves before. I monitored the plants over the next couple of months, when Eltroplectris would be flowering, but there was no sign of flowers. Then, in June 1978, my botanist friend, George Avery (1922–1983), decided to check on them and found a few plants in bloom. It keyed out to Spiranthes adnata, which has since been changed to Pelexia adnata, so I phoned Carlyle Luer and he drove over from Sarasota to officially voucher the species for Florida. There were only 6 or 8 plants and, over the next six years, they all disappeared. Figuring we had lost a new orchid for Florida, a welcomed report in 2004 came from Mike Owen, the biologist at Fakahatchee Strand Preserve State Park, that a single plant of Pelexia adnata had been found in the Fakahatchee Swamp by AmeriCorps volunteer, Karen Relish. More plants were later discovered growing on the rotting trunk of a fallen cypress tree and the orchid is now known from two widely separated stations in the swamp, where it still occurs today.
Perhaps the best day I ever spent with Carlyle Luer was when he took me to locations in the Fakahatchee Swamp where he had photographed Epidendrum acunae and Bulbophyllum pachyrachis, two species that are presumed extirpated from Florida. We didn’t fi nd either species, but our bonus prize was a flowering plant of Dendrophylax lindenii, the fabled ghost orchid (see photo on page 12).
In retrospect, I cannot imagine where life would have led me had I not bought The Native Orchids of Florida in 1972. Thank you, Carl. Rest in peace.
About the Author
Roger L. Hammer is an award-winning professional naturalist, author, botanist and photographer. His most recent book is Complete Guide to Florida Wildflowers. Find him online at www.rogerlhammer.com.
The Research Track of the FNPS Conference will include presented papers and a poster session on Friday, May 15 and Saturday, May 16.
Researchers are invited to submit abstracts on research related to native plants and plant communities of Florida including preservation, conservation, and restoration. Presentations are planned to be 20 minutes in total length (15 min. presentation, 5 min. questions).
Abstracts of not more than 200 words should be submitted as a MS Word file by email to Paul A. Schmalzer paul.a.schmalzer@nasa.gov by February 1, 2020. Include title, affiliation, and address. Indicate whether you will be presenting a paper or poster.
FNPS Endowment Research Grants fund research on native plants. These are small grants ($1,500 or less), awarded for a 1-year period, and intended to support research that forwards the mission of the Florida Native Plant Society which is "to promote the preservation, conservation, and restoration of the native plants and native plant communities of Florida."
FNPS Conservation Grants support applied native plant conservation projects in Florida. These grants ($5,000 or less) are awarded for a 1-year period. These projects promote the preservation, conservation, or restoration of rare or imperiled native plant taxa and rare or imperiled native plant communities. To qualify for a Conservation Grant, the proposed project must be sponsored by an FNPS Chapter.
The Dan Austin Award for Ethnobotany provides up to $1,500 to graduate or undergraduate students studying Florida ethnobotany (the study of the relationship between peoples or cultures with plants native to Florida or Florida ecosystems). These can be current uses or historic uses.
Application guidelines and details are online at www.fnps.org. Click on What We Do/Grants and Awards. Questions regarding the grant programs should be sent to info@fnps.org. Application deadline is March 6, 2020. Awards will be announced at the May 2020 Annual Conference. Awardees do not have to be present to receive an award.
The Florida Native Plant Society
PO Box 278
Melbourne FL 32902-0278
Chapters and Representatives
..............................REPRESENTATIVE ......................E-MAIL
1.. Broward ..................................Richard Brownscombe ................richard@brownscombe.net
2. Citrus .....................................Gail Taylor ....................................gfgtaylor55@gmail.com
3. Coccoloba ..............................Lucy Breitung ..............................lfbreitung@gmail.com
4. Conradina ..............................Martha Steuart.............................mwsteuart@bellsouth.net
5. Cuplet Fern .............................Mark Kateli ..................................cupletfern@gmail.com
6. Dade ......................................Susan Walcutt ..............................walcutts@bellsouth.net
7. Eugenia ..................................David L. Martin ............................cymopterus@icloud.com
8. Heartland ...............................Gregory L. Thomas .......................enviroscidad@yahoo.com
9. Hernando ...............................Janet Grabowski ..........................jggrenada@aol.com
10. Ixia .........................................Jessica Spencer ..........................botanybabe28@yahoo.com
11. Lake Beautyberry ...................Patricia Burgos ............................patriciab1724@gmail.com
12. Longleaf Pine ..........................Cheryl Jones ................................cheryls21660@gmail.com
13 Magnolia ................................Scott Davis ..................................torreyatrekker@gmail.com
14. Mangrove ...............................Al Squires ....................................ahsquires1@comcast.net
15. Marion Big Scrub ...................Deborah Lynn Curry .....................marionbigscrubfnps@gmail.com
16. Martin County ........................Dianna Wentink............................dw18hpc@gmail.com
17. Naples ...................................Kara Driscoll ................................k.dreamflow@gmail.com
18. Nature Coast ..........................Gail Parsons.................................gailpar1@verizon.net
19. Palm Beach County ................Helen Laurence ...........................helen.laurence@gmail.com
20. Passionflower .........................Susan Knapp ...............................suzy5684@aol.com
21. Pawpaw .................................Sonya H. Guidry ...........................guidry.sonya@gmail.com
22 Paynes Prairie ........................Sandi Saurers ..............................sandisaurers@yahoo.com
23. Pine Lily .................................Tayler Figueroa ............................harper.tkf@gmail.com
24. Pinellas ..................................David Perkey ...............................dperkey@hotmail.com
25. Sarracenia .............................Jeannie Brodhead ........................jeannieb9345@gmail.com
26. Sea Oats ................................Judith D. Zinn ..............................jeryjudy@valinet.com
27. Sea Rocket ...........................Greg Hendricks ............................gatorgregh@gmail.com
28. Serenoa .................................Robert Dye...................................mrpyrorat@verizon.net
29. Sparkleberry ...........................Carol Sullivan...............................csullivan12@windstream.net
30. Sumter ...................................Judith Bradley .............................ham1e@aol.com
31. Suncoast ...............................Virginia Overstreet .......................voverstr@tampabay.rr.com
32. Sweetbay ..............................Jonnie Smallman .........................jsmallman2@gmail.com
33. Tarflower ...............................Julie Becker.................................julie.b455@gmail.com
34. The Villages ............................Carol Spears ................................caroljspears@cs.com
Contact the Florida Native Plant Society PO Box 278, Melbourne, FL 32902-0278. Phone: (321) 271-6702. Email: info@fnps.org Online: www.fnps.org
To join FNPS: Contact your local Chapter Representative, call, write, or e-mail FNPS, or join online at www.fnps.org
Contact the PALMETTO Editor: Marjorie Shropshire, Visual Key Creative, Inc.
Email: pucpuggy@bellsouth.net Phone: (772) 285-4286