Alligator Flag is a Snappy Wildflower

29 Mar

Alligator Flag

Thalia geniculata


Which wildflowers have the most complex awesome magnificent pollination mechanisms?  Orchids?  Naw.  Orchids are okay if you like Nero Wolfe, but the truly cool flowers around here belong to Alligator Flag (Thalia geniculata), one of the only two members of the Maranta Family (Marantaceae) native to the United States, and possibly the largest native herb.  The similar Powdery Thalia (Thalia dealbata) grows across much of the southern U.S. but not in Florida to my knowledge.

Thus native plant enthusiasts perhaps don’t encounter the Marantaceae often, but warm-climate gardeners  and interiorscapers enjoy Calathea, Maranta, and Stromanthe.  The popular houseplant known as Prayer Plant is a Maranta.  A quick glance reveals the membership of these plants in the Ginger Order along with Bananas, Birds of Paradise, Cannas, Gingers, and Heliconias.  An odd feature Marantaceae share with Cannas, Gingers, and Spiral-Gingers is that the showy parts of the flowers are mostly derived from stamens (staminodes) instead of the petals, which tend to be inconspicuous.  Floral features we’re about to explore for Thalia are shared in part with some of these kin-plants, especially other Marantaceae.

Thalia geniculata ranges broadly from Florida southward to the Buenos Aires area.   More interesting is are three similar “species” in Africa.  Marantaceae expert Dr. Lennart Andersson interpreted the African representatives to be invasive exotic descendants of American Thalia geniculata relocated to Africa hundreds of years ago, possibly on slave ships.  Although not offered by anyone as an explanation for the boat ride, Florida plant icon Julia Morton mentioned edibility of the boiled rhizome.  An abundant edible “root” in the areas of slave commerce sounds like a food source for the return trip.  Arrowroot starch comes from cousins in Maranta and Canna.


The origin of the name “Thalia” is a head-scratcher.  Thalia in Greek mythology was one of the three graces, daughters of Zeuss, and her name came in turn from a similar Greek word for “blooming,” a perfect name for the graceful plants.  But hold on there!   According to unassailable old botanical references, that’s not where Linnaeus got the name, but rather for Johann Thalus a German naturalist killed in an unfortunate carriage mishap.

Now for those crazy flowers.  This will take some concentration, so listen up, and next time you see Alligator Flag  growing wild, first look for those flagged gators, then examine the flowers.  As with other Marantaceae,  they are in mirror-image twin pairs.  That’s just plain weird (and pretty).  Second, as already mentioned, the showy parts are predominantly modified stamens posing as petals.  Remember the term staminode.  The real kicker, almost literally from the bee’s perspective, is the rat-trap snap pollination mechanism.  When a carpenter bee probes the flower, the style like a botanical rat trap.  Try poking a pine needle or pencil tip into a blossom—you can snap it too unless a bee beat you to it.

Analyzing every floral organ is beyond the scope of our light and fun blog. (Interested readers can reference the journal article noted below.)  But here is the core of it all.  The style is hairpin-bent with the stigma (pollen-receptive organ) a cavity just beyond the bend.  Exactly at the bend is a little cup where the anther (pollen-producing organ) deposited the pollen while the flower was still in the bud.  That is, the flower uses the style to deliver pollen to the pollinator.

The hairpin style, with its scooplike stigma and its little cup of predoposited pollen, lies like a hotdog in a bun inside of a boat-shaped staminode.  Think of a guy lying in a canoe.  Think of Dracula in a coffin.  The boat-shaped staminode has two fingers rising from its side and wrapping  over the cocked style.  Those two fingers are apparently triggers to unleash the snap.  Before the event, the knuckle with the pollen cup is near the mouth to the flower.

When the carpenter bee or your pine needle disturb the triggers(s), the style pops up and curls inward in a split second.  Think of the guy lying in the canoe suddenly sitting up, or Dracula doing the Transylvania Twist.

When the style snaps up and inward, first the stigma scoop scrapes across the bee’s tummy removing any pollen it has brought from a different flower.  Then a nanosecond later in the same snap the pollen-bearing cup brushes new pollen onto the bee.  The snap no doubt kicks out the dismayed bee, and closes off the entrance to the flower, which has no further need for visitation.

[Notes.  John Bradford took the beautiful photo.  The drawing comes from Rogers, G. The Zingiberales (Cannaceae, Marantaceae, and Zingiberaceae) in the Southeastern United States. J. Arnold Arb. 65: 5-55. 1984.]


Posted by on March 29, 2012 in Alligator Flag


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13 responses to “Alligator Flag is a Snappy Wildflower

  1. annsbirdventures

    March 29, 2012 at 1:03 pm

    You can see these close up and “snap” the rat trap at Wakodahatchee Wetlands, west of Delray Beach, FL. Thanks to you, I now have a better understanding of how the heck that works!

  2. George Rogers

    March 29, 2012 at 1:10 pm

    Love Wakodahatchee! That and Green Cay are the only places where folks with cheap lenses can “snap” snazzy bird photos. Have you done those two sites justice in your ornitho-blog?

    • annsbirdventures

      March 29, 2012 at 7:28 pm

      I’ll mention both places. Thanks for the idea. I have mentioned them in my newspaper articles, several times.

      • George Rogers

        March 30, 2012 at 9:29 am

        How about a feature presentation!

  3. Steve

    March 29, 2012 at 6:22 pm

    One time while walking the boardwalk at Corkscrew Swamp Sanctuary, I came across a young male bear (100lbs or so) eating the bases of Alligator flag. I was able to stand and watch him destroy the majority of the plants in the dry down of a Cypress “donut hole”, as he methodically stomped on each plant, and took a bite from base. I’d before seen areas where the Thalia was freshly destroyed, and now I know why. So if the rhizomes and shoots are tasty for bears, I imagine it is good for folks too.

    • George Rogers

      March 30, 2012 at 9:28 am

      Hope that’s not a sign of desperate bear starvation. If bears eat em’, hogs must love em’ although I’ve never noticed hogworks in the Thalia patch.

  4. Tammy

    March 30, 2012 at 3:20 pm

    The Alligator Flag photo is beautiful and I learned so much about them. I also wonder where “Thalia” comes from, rather unusual. I am also an orchid lover but will add these to my list of pretty purple flowers to watch for in Florida.

    • George Rogers

      April 2, 2012 at 11:07 am

      Thanks Tammy. Despite the contrary evidence, I feel in my bones that the name really does come ffrom the Greek “goddess.” Who knows what old Linnaeus was really thinking…maybe he had both sources in his smart mind. Saw a wild orchid with big plump fruits Thursday…wish I knew what flowers made those pods.

  5. friedova

    December 29, 2013 at 5:02 pm

    I visited the constructed wetland at Central Baptist Church on SW Tulip in Martin County this afternoon. The County planted a lot of Alligator Flag here, and, though it is not Green Cay, it has quite an array of birdlife.

    I enjoy your blog, and your most recent on Toxaphene was very informative. I am sure, Ms. Carson, if she was around, would be appalled.

    • George Rogers

      December 29, 2013 at 8:33 pm

      Thanks a million—and for the tip on the constructed wetland on SW Tulip. Will have to go take a look, with John and his camera gear.

    • George Rogers

      January 5, 2014 at 6:56 am

      Thanks Laure, Gonna miss you this term!

  6. Dawn

    September 24, 2015 at 12:58 am

    Thank you so much for the information on this. I have this in my pond on Kauai and it loves it there.. blooms just about all year. Loved the bee information. Dawn

    • George Rogers

      September 24, 2015 at 9:56 am

      Hi Dawn, Beautiful plant isn’t it? There are two large water reclamation areas near here loaded with nutrient-enriched tertiary sewage treatment water, and the alligator flags grow on steroids…


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