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Dogs Beware of the Leafless Swallow-Wort!

12 Aug

Leafless Swallowwort

Cynanchum scoparium

Apocynaceae

An older synonym for this plant contains the wonderfully apt genus name Amphistelma, meaning “surrounding wreath.”  You’ve got to see it to appreciate the name.  This garland-forming vine, which becomes leafless with age, wraps and smothers its host, as botanist John Kunkel Small noted in his Flora.  The intertwined stems twist together in parallel resembling those twiggy grapevine wreaths in arts and crafts stores.  Too bad about changing nomenclature, because the less descriptive prevailing name now, Cynanchum, merely means dog-choker, relating to the handle “dogbane” applied to related species.  The name “swallow-wort” embraces multiple plants in the Milkweed Family and beyond.  It may allude to toxicity.

 

Wandering deeper into the speculation zone, the tendency toward leaf loss with advancing age is an apparent adaption to the vine’s changing circumstances along life’s journey.  Youngsters are leafy, as any proper hammock-understory upstart should be.  But eventually the vine climbs a host plant, breaks forth into the sunny overstory, and sheds its leaves, taking on a more xeriphytic, stem-photosynthetic, low-water-loss active adult lifestyle.  Sometimes it resembles the likewise leafless parasitic Lovevine.

 

Close examination of the small flowers shows them to be Milkweed-ish, that is, having the pollen clumped into packages known as pollinia.   Packaged pollen transfers thousands of grains in a single pollination event.  Not many plants achieve this – with Orchids and Milkweeds (defined broadly) being prominent examples.

The tornado-shaped blossoms have partial barricades at the throat, limiting penetration to the “right” pollinators, whatever they may be.  Butterflies?  Inquiring minds need to know.  Bees and wasps are the only reported pollinators of Cynanchum species known to us, but it is a large genus, and the reports are few and Afro-centric. We prefer butterflies as the prime suspects for those “witch’s hat” flowers, but the truth remains to be seen.

We are dealing with an important insect nursery plant.  The larval guests include the Faithful Beauty Butterfly, first described in Cuba.  Note the species name Composia fidelissima, which predates Fidel Castro, and probably refers to the loyalty of the caterpillar to its vine.  Also in the picture, with details unclear, are the Queen Butterfly and other members of the Monarch Group (subfamily), which  become toxic  from their youthful escapades on Cynanchum scoparium.

The “Giant Milkweed Bug” (Sephina gundlachi) too enjoys today’s vine as its sole breeding host.  Weirdly enough, the mama bug oviposits onto the host plant rather than directly onto the vine.  The bug’s warning coloration is much the same as the Monarch Butterfly and its kin.  This is a possible example of Mullerian Mimicry in which two different noxious creatures mimic each other, reinforcing the effect of their “bug off”  (aposematic, if you will) coloration, much like the black leather, studs, chains and insignia of unrelated motorcycle gangs.

Mullerian Mimic

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The double pods split open to release “parachute” seeds, as in most “Milkweeds.”  (This post is a collaborative effort by John Bradford, Billy Cunningham, and George Rogers exploring the eastern shore of Lake Okeechobee. JB shot the pictures, except for the badass.)

 
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Posted by on August 12, 2011 in Leafless Swallowwort

 

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Swamp Dogwood at the Dump

06 Aug

Swamp Dogwood

Cornus foemina

Cornaceae

With Billy still in North Carolina,   John and George changed venues from the east shore of Lake Okeechobee to the east shore of the Palm Beach County Solid Waste Authority.  Seriously,  take a hike at the dump!

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Scenic Lake Altman at the Landfill, No Fishing, Waste-to-Energy Plant in the distance. Photo by GR.

The flora and critters there are diverse and interesting, so picking a featured species was controversial.   The Swamp Dogwood was in full bloom, making it necessary to address the question of why Dogwood is called Dogwood.  Now, if you believe what you find on Google, it comes from “dag” wood, because the wood made “daggers,” or cattle prods.  That is credible because the wood is hard, tough, and pretty.     George carves archery bows, and made one of a stave of Pacific Dogwood.  Took months, and yielded a beautiful bow, which snapped in a brittle moment, perhaps a victim of Anthracnose?  (See below.)   The wood has served for tennis racquets and heads of golf clubs.  George worked long ago as a commercial loom operator and owns (but can’t find) an antique dogwood loom shuttle tough as nails.

Cornus foemina by JB

Dogwoods are examples of the once-continuous forest around the northern hemisphere, broken up over the eons by climate and environmental change leaving  pockets of floristic similarity especially in eastern Asian and in the eastern U.S. with additional remnants in Europe and occasionally along the U.S. Pacific Coast.  Dogwoods inhabit all of those places.  Four species are native to Florida, only one in our area.

The genus Cornus has about 60 species.   Perhaps the most famous and showiest is the Flowering Dogwood, Cornus florida, which does occur in Florida.  This gorgeous species and others suffer  from an introduced destructive fungal “Dogwood Anthracnose” disease.  The disease appeared first in the Pacific and in the Northeast in the 70s and early 80s.  By the early 90s, Dogwoods in some areas were devastated.  So far—as far as we know—the fungus has spared Florida.

Here is a little trick to identify Dogwoods in the field.   First of all, most species have opposite leaves with beautiful curved veins.  Snap a leaf and gently pull the two pieces apart.  In Dogwoods thin threads will cross the gap and bind the two halves together.

Today’s species, Swamp Dogwood, has white starry flowers in showy clustered, followed by more or less blue “berries” (drupes)  not fit for human consumption but is food for the birds and wildlife. (This post is a collaborative effort by John Bradford and George Rogers.)

 
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Posted by on August 6, 2011 in Swamp Dogwood

 

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Devil’s Claw Will Gitcha!

04 Aug

Devil’s Claw

Pisonia aculeata

Nyctaginaceae

Here’s a trivia question for flower-buffs: What do Devil’s Claw Vines in the forest, Bougainvilleas at the hotel, Four O’Clocks in the garden,  Blollies on the dunes,  Beach-Peanuts on the sand, and Red Spiderlings in the rough have in common?

You guessed it—they are all members of the Nyctaginaceae family.  And that gem underscores the importance of learning plants by families, not just one at a time.  If you know some of these species, do you see the family resemblance?   The Devils Claw leaves and branching pattern look like Bougainvillea.  A lot of Nyctaginaceae have colorful bright reddish-purplish pigments—Bougainvillea, Four O’Clock,  Beach-Peanut,  Red Spiderling,  even the Blolly fruit.    The colorful “flowers” have no petals.   The colorful parts are bracts, that is, modified leaves associated with the flowers.    There are also sepals, and the fused sepals can make a tube, this often tightly enclosing the one-seeded fruit.

In today’s plant as the sepals enclosing the fruit have odd rows of protruding glands to help the fruit cling to passing animals.  They are are gummy-sticky.

Recurved claws

The name Devil’s Claw  comes from scary back-curved spines.   We know the pain from recent ankle-bleeding experience.    But why have curved spines for self-defense when straight bayonets are more to the point?     Perhaps reverse-curvation helps the vine cling to its host trees.  Hurricane country,  after all.  Under ideal conditions, Devil’s Claw can graduate from its lowly clinging vine status to full-blown treehood.

The plants are either male or female, that is, they are dioecious, and the male and female flowers differ.   The male flowers are bowl-shaped and yellowish;   the females  are narrower,  more constricted, with a comical brushy stigma resembling the tuft on Jeff Dunham’s friend Peanut.  (Huh?  Just Google Image it.)

Male flowers

Devil’s Claw occurs throughout much of the American Tropics, including South Florida, and now extends around most of the warm-climate world,  no doubt due to artificial introductions.  (This post is a collaborative effort by John Bradford and George Rogers on the east shore of Lake Okeechobee.  JB took today’s pictures.)

 
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Posted by on August 4, 2011 in Devil's Claw

 

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Santa Maria Feverfew Packs a Punch

30 Jul

Santa Maria Feverfew

Parthenium hysterophorus

Asteraceae or Compositae

Parthenium (Today's photos by JB)

Continuing our exploration of the eastern shore of Lake Okeechobee today, John and George wallowed in invasive exotics, eating guavas, tripping over Syngonium vines, and admiring the tallest Johnson Grass we’ve ever seen.  (Billy is in North Carolina.)  Part of the fun was spotting one isolated little Coontie, which is native.  Has it been there a millennium? Did Native Americans bring it?  Did a seed float across Lake Okeechobee in a storm?  Does it date from someone dumping garden refuse?  Why is a Cycad the opening act for a post on Parthenium anyhow?  Well, they are both bioactive and toxic.

Let’s get on-topic.  An intriguing non-native plant loitering around the agricultural field borders is Santa Maria Feverfew (Parthenium hysterophorus), probably native from Mexico to South America.  It is now a worldwide weed, which tends to obscure the precise point of origin.

A clue to the strange brew within, the foliage has a distinctive odor when you crush it, which is a bad idea, as the itchy-scratchy sap can raise a few blisters.  Despite the hazard, it is fun to sniff weedy members of the Composite Family, because they tend to contain sesquiterpenoid lactones.

Huh?  Back up a second here.  Terpenoids (TURP-ah-noids) are usually pleasantly fragrant botanical essences, such as pine, lemon,  citronella,  and menthol.  They are based on 10-carbon “terpene” chains.  Just as a sesquicentennial is  150 years, a sesquiterpenoid (SES-kwa-turp-ah-noid) is a terpenoid-and-a-half, that is 15 carbons, and the term “lactone” (LACK-tone) refers to specific molecular configuration beyond the scope of our little e-chat. All right now,  don’t get hung up on the chemistry—the point here is what the chemicals do.   Sesquiterpenoid lactones tend to have a characteristic bitter or medicinal odor, not necessarily unpleasant, and, although found in multiple plant families, they are the flagship anti-herbivory arsenal of Composites, including Feverfew.  Parthenium contains a medicine cabinet of sesquiterpene lactones as well as other toxins.  The best-known lactone in today’s species is named for it, parthenin.

Pretty little snow white flower heads on Parthenium. It looks better than it smells.

Sesquiterpenoid lactones are a veterinarian’s (and butcher’s) nightmare.  Especially hard on sheep and goats, they’re not so great for cattle and horses either.  The compounds attack vegetarians in varied nasty ways—they are neurotoxic, and able to bind to animal tissues interfering with varied functions, and prone to cause digestive lesions.  They cause “spewing sickness,” where the animal can drown in its own vomit.  These toxins spoil the meat of livestock who eat them.

And here is an odd effect with possible benefits in human medicine: antimicrobial activity.  What would a plant do with antibiotic capability?  Apparently the sesquiterpenoids interfere with the microbe symbionts in the animal rumen, adding even more injury to the error of eating the wrong weed.

The compounds have insecticidal characteristics too, harnessed in some regions where Parthenium helps with flea control.

A fine line separates scary poison and useful medicine.  Species of Parthenium have served historically against diarrhea, bacterial infections, malaria (some partheniums are called “wild quinine”), female troubles, pain, and fevers.   But watch out, Parthenium derivatives reportedly damage human chromosomes.

If you are a plant, who do you want to suppress in addition to hungry grasshoppers and goats?  Answer: competition from other weeds.  One study showed parthenin, mentioned above, to thwart germination, to diminish the chlorophyll content, and to sabotage enzymes in a species of Ageratum.  Maybe it has commercial value as a natural herbicide, but we don’t really want to handle it!

The botanical name is just plain odd.  The name Parthenium is of debatable origins that we’ll ignore.  The weirder part, hysterophorus means womb-bearing.  What was Linnaeus thinking?  Not clear, but the flower heads do look like the ends of the fallopian tubes.

Many members of the Composite Family contain latex.  A related species, Parthenium argentatum, is the source of the rubber substitute guayule.

What a plant: it’ll cure your cooties, mutate your offspring, make the goat barf, give a horse a crummy in his tummy, sour the lamb vindaloo, irritate your skin, and self-weed the garden.  Yet it looks so white-flowery innocent by the side of the canal.  (This post is a team effort by John Bradford and George Rogers.)

 
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Posted by on July 30, 2011 in Santa Maria Feverfew

 

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Sugarberry

24 Jul

Sugarberry
Celtis laevigata
Cannabaceae

Yesterday (July 22) we braved 90-degree heat, ear-tickling gnats, and spider webs resembling fishnets to explore the wooded area along the east rim of Lake Okeechobee near Pt. Mayaka . The biggest trees are Bald Cypresses which are older than the Hoover Dike, but they appear to be past their prime, thanks no doubt to the de-swampification of the lake perimeter by the dike, rim canal, and surrounding sugar fields. And there are plenty of awesome Strangler Figs, mixed with the occasional Mastic.

East shore of Lake Okeechobee as John Kunkel Small encountered it before we did. Photo by JKS.

The new kids on the block are Sugarberries taking over with the coverage and vigor of Melaleucas, but Sugarberries are native members of hardwood hammock communities. They are an example here of “natives gone wild.” In an unnatural disturbed habitat it looks like they can romp. Underscoring that effect is an adjacent monoculture carpet of Pepper Vine (Ampelopsis arborea) extending unchallenged from the forest edge to the edge of the rim canal.

Sugarberry. (All contemporary photos in this post by JB)

Sugarberry ranges across much of the southern U.S., extending southward into Mexico in scattered localities. Celtis is a large widespread genus, containing also the well known Hackberry (Celtis occidentalis). These plants have resemblances to Nettles, Elms, and Trema, a messy circle of kinship when it comes to family classification. Varied slicings, dicings, and clusterings have yielded different family definitions and ever-changing family assignments for Celtis over the years. In our era of precision DNA-guided classification, it looks like the Ganja Family, Cannabaceae, may be the family of choice. Please don’t smoke the Celtis, but do enjoy its sweet little fruits. Sugarberry and similar Tremas have been called “Nettletrees” in the past. The leaves look somewhat like those of nettles, and a more interesting similarity is in the flowers. The stamens are bent like a trap spring, and at the moment of truth, they straighten BAM! and fling the pollen explosively.

Warty bark

Sugarberry is easy to recognize, with vaguely triangular leaves having lopsided bases. The bark is distinctively warty, which may be contagious to tree-huggers.

Those sweet pea-sized fruits pack their entire flavor into a cheap thin layer around a massive stone. It almost seems like bait and switch to the hungry birds who no doubt expect more flesh in exchange for dispersal services.  Around the world many peoples have valued the sweet flesh and ground fruit stone as foods, medicines, and condiments, often dried and pulverized. Native American names for the fruity pebbles translate loosely as “crunchy.” The relationship of Celtis to pre-European Floridians ran deep. Celtis iguanaea and C. pallida in Florida occur more or less exclusively, or at least preferentially, on Native American middens, and speaking of historical value, the bendable wood makes good bows, and it serves flexibly in basketry.

Crunchy fruit snacks

Sugarberry has a place in modern landscaping too. It is “the” tree of the Jupiter Post Office, and is especially noteworthy there producing thousands of seedlings covering the lightly maintained “lawn,” demonstrating how this species can go postal, given a chance.

This report is a collaborative effort by John Bradford, Billy Cunningham, and George Rogers.

 
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Posted by on July 24, 2011 in Sugarberry

 

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Hog Plum

20 Jul

Hog Plum, Tallowwood
Ximenia americana
Ximeniaceae

How many Florida native species are worldwide?  Few, and Hog-Plum is one, occurring in sandy windblown places, often more or less near the sea, from Florida to Australia.  The fruits float, apparently over long times and over long distances, and birds probably help get them around.  The name “Hog Plum” is confusing because a plant better known under that name is Spondias mombin, which has a similar orange drupe.  In parts of its range Ximenia americana is important in the kitchen and in the pharmacy.  For instance, in Cameroon it is cultivated for raw fruits, for fermented drinks, and for its combustible oil.  The seeds contain cyanide, limiting the culinary value of the oil, which nonetheless seems to have cooking applications, as well as uses in personal grooming.  Reported medicinal uses for products from this thorny shrubby species are numerous, including treatment of scars, worms, leprosy, and sexual problems, hopefully not simultaneously.  Ximenia caffra is a related African species likewise grown for its edible fruits and for the abundant oil in its seeds.

Hogplum fruits

A second oddity of Hog Plum is that, like several other scrub species, it is a partial parasite, ripping off the roots of neighboring plants.  Additional scrubbish species of similar inclinations in our area include Black-Senna (Seymeria pectinata), Love Vine (Cassytha filiformis), and Graytwig (Schoepfia schreberi aka S. chrysophylloides).  Parasitism is an apparent adaptation to life in nutrient-poor sands.

Hogplum flowers in July

The flowers are oddly bearded on the inner surface, probably to exclude unwelcome nectar thieves while allowing “proper” bee pollinators, and/or the hairs may be tactile nectar guides to visiting bees.  Honeybees are reported to be effective pollinators, although some very limited fruit-set occurs even with pollinator exclusion. [This post is a collaborative effort by John Bradford, Billy Cunningham, and George Rogers]

 
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Posted by on July 20, 2011 in Hog Plum

 

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Marsh Gentian

18 Jul
Marsh Gentian
Eustoma exaltatum
Gentianaceae
 
Some wildflowers are so big, colorful, and assertive, they look like they came right out of a Garden Club flower show. That is not far from the truth. This eye-grabbing species is, according to contemporary taxonomy, the lone species of the genus Eustoma, a member of the Gentian Family. In South Florida we may think of it as a marsh or coastal species, but amazingly, this beauty inhabits diverse moist habitats from South America to Florida and even ranges as far as Montana. Ladybird Johnson would have called it “Texas Bluebells.”

The species tolerates salty and alkaline conditions. The photo on our blog was taken just steps from the Intracoastal Waterway at the edge of a mangrove stand, a stone’s throw from Tiger Wood’s home.

Marsh Gentain

Marsh Gentain

 

These plants have a complex taxonomic and horticultural history. The garden Eustomas are best known under the names Eustoma grandiflorum or E. russellianum, or under the genus name Lisianthus. They are so well established under the last-mentioned name, that “Lisianthus” lives on as their handle in the commercial trade. Current classifications tend to regard all of these names as synonyms of E. exaltatum, making our wildflower and the vast array of garden Lisianthus one and the same species.

The plants are highly modified horticulturally and inter-crossed, yielding numerous cultivars with purple, violet, bluish, pink, white, single, and doubled blossoms. They are valued as garden selections, as potted plants, and especially as cut flowers. Many of the doubled cultivars resemble roses. Starting with attention in Japan in the 1930s, this species came (back) commercially to the U.S. in the 1980s and quickly became the number one cut flower in the U.S. although production problems emerged. Several cultivars have been developed in Florida, but Japan remains the capital of Lisianthus.

Marsh Gentain

Marsh Gentain

The flowers are self-compatible, and an example of “protandry,” that is, with pollen released days before the stigma becomes receptive.

Personally, we regard native wildflowers as more beautiful than any artificial garden, but the “Marsh Gentian” is a species that graces everyone’s world from Florida natural areas to the Japanese cut flower industry.

 
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Posted by on July 18, 2011 in Marsh Gentian

 

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Underground Botany: Hidden Flowers and Buried Fruits

16 Jul

What do Innocence, Blue Maidencane Grass, Bog White Violet, and Beach-Peanut have in common? Hint: Look at the title of the post. They all have “funny” flowers and fruits doing things you don’t expect where you don’t expect them.

Houstonia procumbens 2

Innocence

Innocence (Hedyotis procumbens) is a petite member of the Coffee Family (Rubiaceae) related to the Bluets familiar to readers with more northern exposures. In South Florida the species turns up on sun-baked dry sugar sand in scrub or near-scrub habitats. The small white flowers often appear to spawn directly on the sand, as the vegetative plant body is low, trailing, and frequently more or less covered with sand. After flowering, the flower stalk bends earthward burying the developing fruit protectively for subterranean maturation. To be speculative, it looks like ants might disperse the resulting fruits and seeds. And there is more to the story: Innocence is not so innocent. In addition to the showy flowers, it hides secret inconspicuous flowers underground. These either self-pollinate or do not require pollination, and they produce fruits without seeing light of day. Such flowers are a “back-up” on the sexual process and are called cleistogamous (kleist-OG-ah-mus) flowers. Cleistogamous comes from Greek for, roughly speaking, “hidden husband.”

The most famous owners of cleistogamous flowers are violets, and our native Bog White Violet (Viola lanceolata) is no exception. Look for the hidden flowers or the resulting fruits near the base of the plant.

Bog White Violet

Bog White Violet

A more surprising case is the grass Blue Maidencane (Amphicarpum muhlenbergianum, see http://www.floridagrasses.org). Amphicarpum translates as “fruits on both sides“, in this case, both sides of the ground surface. In addition to normal (chasmogamous) flowers and fruits in the sunshine, cleistogamous flowers in the rhizome make buried fruits. John and I saw these first and most easily in an area rooted up by feral hogs.

Blue Maidencane

Blue Maidencane

Blue Maidencane Buried Fruit

Blue Maidencane Buried Fruit

Buried fruits are hidden from some menace, and what could be more menacing than clinging to life on Florida seashores and seaside dunes. You can guess now how Beach-Peanut (Okenia hypogaea) got its name. Not for being a type of goober. The Beach-Peanut is no legume, but rather a member of the Four O’Clock Family (Nyctaginaceae), as you might guess from its vibrant floral display. The prettiest flower on the beach buries its fruits in the sand on a downward peg potentially mistaken for a root. It too produces cleistogamous flowers, but the relative roles of the cleistogamous flowers and showy flowers remain poorly studied.

Beach-Peanut

Beach-Peanut

 
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Posted by on July 16, 2011 in Beach Peanut, Blue Maidencane, Bog White Violet, Innocence

 

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American Crinum and the Lubber Grasshopper

15 Jul
Crinum americanum 2

American Crinum

Some of the largest and most eye-catching wildflowers in Florida are aquatic, and the American Crinum is in that category, featuring garden-worthy fragrant blossoms a couple inches in diameter, having 6 long white“petals” and a long narrow tube.

Big white long-tubular flowers are pollinated by sphinx moths (also called hawk moths), which are nocturnal and are drawn by scent instead of by bright colors. There are two species of sphinx moths in South Florida and their relative importance with respect to Crinum sex is unclear. They hover when they visit the flower and unroll a long proboscis that matches the narrow floral tube like a key in the lock. The larva of the Tersa Sphinx Moth resembles a snake.

The insect relations of Crinums run deeper than pollination assistance. As is true of many members of the Lily Family, Crinums contain bioactive alkaloids. Alkaloids are familiar as drugs, such as nicotine, caffeine, heroin, morphine, cocaine, and colchicine. Crinum americanum is a one-species chemical factory with at least 11 known alkaloids. It and other Crinums are the subjects of optimistic drug research, and our species may well wind up saving somebody from something someday. Looking back, Crinums have rich histories in traditional and local medical practices around the world. One Lily alkaloid is already useful against gout. Actually American Crinum poison does save somebody from something already: Lubber Grasshoppers from being bird snacks. Eating the drug-laden foliage on wild and garden crinums, Lubber Grasshoppers render themselves toxic, revealing their acquired threat to hungry birds with bright warning coloration.

Lubber 5 (small)

Lubber grasshopper eating Crinum folage

Crinum americanum is the U.S. representative of the 100-species genus Crinum, which comes mostly from the Old World Tropics. DNA study shows the closest relatives of the American Crinum to be the other Crinums from Tropical America, leaving their relationship with the bulk of the genus in Africa and beyond unclear. How did they cross the sea? And when?

Crinums are prominent and diverse in warm-climate gardens, with numerous species and cultivars having white to reddish and purplish flowers. They are hybridized and highly modified horticulturally, making the exact taxonomy of the garden crinums tangled and puzzling.

 
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Posted by on July 15, 2011 in Lubber Grasshopper, String Lily

 

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