Pink Redstem

21 Dec

Ammannia latifolia

(Johannes Ammann was an 18th Century botanist.  Latiflolia means wide leaves.)


John and I worked at Haney Creek Natural Area near Jensen Beach, Florida, this week.  Much to my delight as a lover of things in wet places, we saw an old wetland oddball plantfrind, always under-appreciated.   The sort of plant you step on looking for something “interesting.”    It is all interesting if you look closely, or if you read research by other people, especially other people with an electron microscope.   Today I’m paraphrasing an eye-opening paper by Dr. Shirley Graham (in the Journal of the Arnold Arboretum, vol. 66).  Because the work dates to 1985, I’m confident Dr. Graham and the Journal would have no objection to reappearance in a 2019 blog, and I sent her an e-mail to make certain.

Today I was doing what I like to do, walking along the dried out shore of a nearby stream-canal where only two living things were visible on the barren mud, one a green alga, the other, as at Haney Creek previously, scattered individuals of Ammannia latifolia livin’ the vida sola.  Just desolate mud, a little algae, and big red Ammannias.

Ammannia on mud

What dis the Ammannia and I have in common?  We were alone on the  lifeless mud.

Life “on mars” takes a fairly special plant.  Ammannia has some obvious advantages for places that alternate between flooding and drought, with suffocating soil.    It is a wee bit succulent, has rugged leaves, has red coloration which may be sunscreen,  and has padded little pea-sized capsular toothcup fruits.   The flowers may or may not have petals, that’s odd, and it can sometimes, or perhaps predominantly, set seeds without benefit of outside pollination, a handy trait in a lonely pioneer.  The pollen-making anthers can break off and adhere to the pollen-receptive stigmas in the same flower assuring self-pollination emphatically.  The roots tolerate saturated mud.

Ammannia close

That is all well and good, although perhaps unthrilling.  The magic is in the seeds, as Dr. Graham related.  The electron microscope photos below are from her 1985 publication.

The seeds are  packed a couple hundred per fruit.   They float, and have a special mechanism to do it well:  On one side of the seed there appears a small puffed up beer belly, a flotation device, which collapses when the seed dries.

Ammannia latifolia seeds dry and wet

Seeds photographed today.  The one on top is dry.  The one on the bottom is moist,  the puffed out float on the left. with light shining through.   As the seeds take on water out pops a bubble as seen lower right.

Ammannia coccinea seed with flaot

Ammannia seed showing the pufferbelly.  Photo from sources noted in text.

Even weirder, there are hairs on the inside of the seed coat, wrongside-in.  When the coat is moistened the hairs pop outward to become spikes like the antennae on Sputnik, where they may help water enter the seed.

Ammannia coccinea evaginated hairs

Seed hairs moistened and sticking out.  Photo source mentioned in text.

The moistened seeds become a little sticky, which may help them grab hold to a final sprouting site, or may help them cling to a bird’s leg en route to the next aquatic environment.    The seeds are willing to germinate in a few days under favorable circumstances,  and if things aren’t optimal some are patient and tough, reportedly germinating from dried museum specimens 27 years old.


Posted by on December 21, 2018 in Uncategorized


7 responses to “Pink Redstem

  1. Flower Roberts

    December 22, 2018 at 11:47 am

    What an amazing little seed.

    • George Rogers

      December 22, 2018 at 12:02 pm

      magic beans

  2. Deb Scott

    December 22, 2018 at 11:50 am

    Fascinating. Thanks!

  3. theshrubqueen

    December 22, 2018 at 3:51 pm

    Very festive Pink Redstem and magic beans is a great name for the seeds – germinating after 27 years.I think long viable seeds is a Florida thing, I am pulling weeds from seeds buried in the 60s. 70s and 80s and yesterday…

    • George Rogers

      December 22, 2018 at 4:31 pm

      You might be unearthing seeds from the 1760s….amazing thing about the seeds from the museum specimens…they are fumigated on top of being heat-dried and stored in insecticides in total darkness

      • theshrubqueen

        December 22, 2018 at 4:56 pm

        What is truly amazing is the Bidens

  4. Barbara Levy

    December 22, 2018 at 10:32 pm

    Wow. What a tough plant. My husband just brought home a stray 4-month old male kitten with some toughness similarities! But the plant doesn’t growl a warning while it sows seeds, at least! Great photos too!


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