Something Old, Something New, Something Borrowed, Something Blue

26 Feb

Skyblue Lupine

Lupinus diffusus



[Fertilizer 101:  In descending order of abundance, plants need mostly nitrogen, much phosphorus, potassium, and several “minor” and “micro” nutrients, including prominently iron.  Nitrogen is abundant in the air, but microbes must convert that nitrogen gas to the nitrate and ammonium plants use.   Plants often have trouble acquiring phosphorus, because it does not flow in with water as nitrogen does.   The plant root or fungi associated with the root have to “go get” phosphorus.  Plants in scrub sand have automatic nutrient challenges in that ultra-poor soil.]

Out seeking eagles today, John jumped about 5 feet into the air, mumbling something about “red touches yellow.”

Eastern Coral Snake 1

Something yellow, something black sneaking up behind your back.  (Except where indicated differently, today’s photos by John Bradford.)

Near the sneaky snake we found the pretty plant of the day…Skyblue Lupine.   And here is its mystery:   out in the sugar sand scrub most plants look like they belong growing in a sun-cooked nutrient-deficient sandbox.    They tend to have tough demeanors.   Their gnarly adaptations are what make scrub fun to photo.   But Lupines, by contrast, look robust, green, lush, and perky.   How does the Lupine do it?    How does a Lupine on the sterile sand look like a Garden Club flower out of a nice fertilized flower pot?

Lupinus diffusus 6

Too spunky for a scrub plant!

There may be an answer or two.   It is a Legume, and Legumes have nitrogen-fixing bacterial root nodules to capture that atmospheric nitrogen   Nitrogen problem solved.   True and  nice,  but just the first chapter in a better story.  How bout the second-most limiting nutrient, phosphorus?

Here we must turn to other Lupine species and extrapolate speculatively.   Multiple hundred Lupinus species color the world, including the length of North and South America along the Rocky Mountains and Andes, and much more.  A handful decorate Florida, some native.  Only one is indigenous to South Florida, L. diffusus.    Now back to phosphorus.

Students from my classes, I hope might say, “symbiotic fungi help plants get phosphorus by digesting soil organic matter and sharing the booty with their host roots.”    But oh yea….that scrub soil has no organic matter, and Lupines do not have (or not much) helpful root fungi.    By the way, Lupines collectively are famous for tolerating terrible soils.   In their sterile ground they need a plan-B to get their P:

Back in the 80s botanists caught on to what were called “Proteoid Roots,” discovered first in the plant family Proteaceae.    Since then such roots have turned up in additional plants, making the newer name “Cluster Roots” better.   Cluster Roots look like a bottlebrush.    Guess what stimulates their formation?  Low phosphorus.   Guess what plants outside of Proteaceae can form them to counter low P?    Some Lupines, although as far as I know, L. diffusus remains unchecked, and we can’t dig it in a state park to see!

lupinus cluser roots ajb 10 263 2013 Michael Shane

Lupine Cluster Roots (Michael Shane, Am. Jour. Bot. 100: 263. 2013)

Cluster Roots are not mere brushes.  They are dynamic chemical factories.  The sorts of chemical activities associated with Cluster Roots occur as expected in Lupines with Cluster Roots.  And a little surprisingly, the “Cluster Root functions” turn up also in Lupines where Cluster Roots are unknown.   What are those magic functions?

First and foremost, they secrete citric acid (aka citrate) and similar compounds able to displace phosphorus from soil particles, busting P loose for the plant.   Reportedly as much as 1/3 of the photosynthetic product of some Lupines winds up as excreted  citric acid.  And it gets better:   Citric acid can free inorganic phosphorus, that is,  from soil minerals themselves, not just from (that absent) decaying organic matter.

Lupine roots release supplemental enzymes called phosphatases that liberate even more phosphorus while additional secretions adjust the soil acidity, probably to support  the phosphatase enzymes and/or to help bring in iron, which is sensitive to soil acidity.  But there’s a problem:

Soil microbes digest citric acid.  No worries, Lupines put out soil antibiotics to thwart the little pests.  That’s doubly useful because citric acid helps chaperone iron into roots.  Citric acid helps so much with iron and phosphorus uptake, some commercial fertilizers include it as an ingredient, sometimes hand-in-hand with potassium as potassium citrate.

lupine fertilizer

Factories put citrate (citric acid) in the bag along with P (the P2O5 on the label above).  Lupines make their own citrate,  and borrow their P from the soil directly.

That’s a lot on nutrients.  So here’s the upshot.  All this helps explain something old, something new, something borrowed, and something blue.

Something old:

Lupines as crops date back thousands of years, valued for growth on poor soils.   Explained!

Something new:

Lupines are future crops precious in a starving world with poor soils to farm and phosphorus fertilizers becoming  expensive.

Something borrowed:

Phosphorus fertilizers are pollutants.   But Lupines merely borrow P from the soil, then give it back when plowed under,  even helping support other crops.  No polluting P added!

Something blue:

How many blue wildflowers are there?  (Few)

Lupinus diffusus 7

The pods are woolly.


Posted by on February 26, 2016 in Skyblue Lupine, Uncategorized


Tags: ,

14 responses to “Something Old, Something New, Something Borrowed, Something Blue

  1. richard424

    February 26, 2016 at 10:02 pm

    I am a big fan and follower of your blogs. I was a little disappointed today when the snake was not identified. Not every one knows the rhyme. Everyone in Florida should in my opinion know how to distinguish the two similar snakes.


    Sent from my iPad Richard Lyons 20200 SW 134 ave Miami, Fl. 33177 305-251-6293 (South Florida content) ( world wide information)


    • George Rogers

      February 26, 2016 at 10:39 pm

      I think you are even more right than you know. I criticism I get in the classroom is, “quit assuming what people know.” And I feel it so often in reverse annoyed when I’m the one not in on the joke. Sometimes in the blog non-identifications are deliberate when there’s doubt. But no doubt this is an Eastern Coral Snake. Venomous. The rhyme is,”red touches yellow, kill a fellow, red touched black, friend of Jack.” When red touches black a harmless scarlet king snake mimic of a coral snake. Thanks for the reminder Richard. Good point taken to heart.

      • Martin

        February 26, 2016 at 10:52 pm

        And here’s another one, that I always taught as an alternative to the poem- think of the two negative colors on a traffic light, red and yellow. If the two negative colors are touching, well, you know what to do. Carry on.

        Martin—I like that!. Good for kids and enviro-education and you could make a great graphic. To be honest, all the same to me. I’m so snake-o-phobic, I do a broad jump first and think later…

  2. mossyglen

    February 27, 2016 at 6:15 am

    Thanks to you and John for the chemistry lesson. We were looking for the lupines last week and thought maybe they got cut down along the roadside?? Where should we look when we go back? Hawks Bluff lupines are done blooming.

    • George Rogers

      February 27, 2016 at 9:35 am

      They were in flower yesterday at Atlantic Ridge State Park.

  3. Scott Sincerbeau

    February 27, 2016 at 6:24 am

    You are the best, great job. SometimesI forget the symbiotic part. Thank you.

    • George Rogers

      February 27, 2016 at 9:32 am

      Morning Scott! Enjoying your FC posts…always funny. Symbiosis makes the world go round.

  4. theshrubqueen

    February 27, 2016 at 8:35 am

    Interesting as ever, I saw a huge corn snake near the Lupines at Hawks Bluff. Do you think those Lupines would grow in a garden of scruburbia sand?

  5. George Rogers

    February 27, 2016 at 9:31 am

    Corn snakes always startle me…so weird and snakey looking. But fun to see. I’d like to try some Lupine seeds to see te roots, but such a pretty flower not much cultivated and not at seems a tough challenge.

  6. FeyGirl

    February 27, 2016 at 11:49 am

    WOW! What a treat (!?!?!?)… I always just ran into the harmless bigger guys. Once I had the thrill of hearing a rattle while tromping through some underbrush, of course to try to get a photo of a gator (wink) — but that was the extent of my thrills with the dangerous FLA snakes! The rest were mimicries. Lucky you!

    • George Rogers

      February 27, 2016 at 12:03 pm

      Funny how infrequent encounters with poisonous snakes are, knock wood, despite, like you, out in the weeds and water constantly. But of course all it takes is one false step. I was in the ER waiting room…waiting for a friend with heart trouble when a guy came in with a fresh coral snake bite. Yikes! He was miserable, and the guy who brought him in said it was bad.

      • FeyGirl

        March 2, 2016 at 11:45 am

        WOW… I guess I’ve been lucky then, with all my trampling through those everglades! Of course, I wear taller hiking boots, even in the dead of summer, for that very reason. Those snakes would have to REACH!

        Right…me too. for tromping where I can’t see, I wear boots up to my shins. One little ankle biter will ruin your whole day. Good for thorns and prickly stuff too.

  7. leonorealaniz

    February 27, 2016 at 9:16 pm

    The seed pods look like a furry cluster of critters. Fine photograph of the cluster root. Their arrangement echoes the pattern of the flower/eeds arangement: Elongated in a linear fashion.

  8. George Rogers

    February 27, 2016 at 10:57 pm

    Leonore, What a pleasure to see you! Stole that picture from somebody smarter. Nice point on the echo. Good eye—so true and the resemblance missed me. Might have the same genetic underpinnings? You making prints now? I hope.


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