07 Aug

Dalbergia ecastaphyllum Fabaceae Here’s a quiz: Where can you go to see Acrosticum species (Leather Fern), Caesalpinia bonduc (Nickerbean), Chrysobalanus icaco (Cocoplum), Conocarpus erectus (Buttowood), Dalbergia ecataphyllum (Coin Vine), Laguncularia racemosa (White Mangrove), Rhizophora mangle (Red Mangrove), Ximenia americana (Hog Plum) as dominant local species? If you said along the brackish lower Congo River in Angola you’d be correct.   (Or if you said along the brackish lower St. Lucie River where John and George explored today you’d also be correct.) That’s what’s so fun about mangrove-habitat species…they make you feel cosmopolitan. Those salty species get around, and one of the widespread botanical wanderers is coinvine, named for its floating coin-shaped pods encountered often washed up on beaches.

Coinvine coins

Coins on the beach

The coins don’t look much like legume pods, but they are.   Come to think of it, the simple leaves don’t look much like the compound leaves characteristic of legumes either. The little white pea flowers are legume-ish and so are the nitrogen-fixing root nodules in Dalbergia species.

Coinvine in flower (by John Bradford)

Coinvine in flower (by John Bradford)

The nitrogen-fixing angle is interesting. Why do plants have symbiotic bacteria housed along their roots? To extract nitrogen from the air and make their own nitrogen fertilizer.   That ability might help explain the ability of coinvine to occupy nasty soils.    But there’s more.  Coinvine does not merely tolerate poor soils, it tolerates poor salty soils, and that introduces a kink.

50 cents (by JB)

50 cents (by JB)

Most legumes have species of the bacterial genus Rhizobium as their nitrogen-fixing symbionts.   But now for that kink.  The large bacterial genus Burkholderia, some of its species pathogenic, started turning up as nitrogen-fixing symbiont in a variety of plants, including an increasing number of species of Dalbergia.  Dalbergia ecastaphyllum is characteristic of salty and alkaline habitats.   Research shows Burkholderia soil species to be especially salt-tolerant and to increases salt tolerance  in host plants, and although with the data thin and sketchy, this bacterium has spawned interest as potentially useful to boost crop yields on saline soils.   Too bad spare change doesn’t really grow on vines.

Coinvine (by JB)

Coinvine (by JB)


Posted by on August 7, 2015 in Coinvine 1, Uncategorized


9 responses to “Coinvine

  1. theshrubqueen

    August 8, 2015 at 8:05 am

    Thanks, I saw some Coinvine last week at the Sebastian Inlet and was wondering what it was! Feeling oh so cosmopolitan now.

    • George Rogers

      August 8, 2015 at 10:42 am

      Nice to be useful…such a rare sensation

      • theshrubqueen

        August 8, 2015 at 11:22 am

        I can assure you I am much more useless, is Botany Companion a new blog?

  2. Annie Hite

    August 8, 2015 at 9:39 am

    I’m seeing coinvine at the Jupiter Inlet Lighthouse Outstannding Natural Area and at Jupiter Ridge Natural Area. Thought I read somewhere that the plant was used by native Americans to stun fish???

    • George Rogers

      August 8, 2015 at 10:41 am

      Not sure about the fish but likely given the legume toxins in the plant

  3. Steve

    September 6, 2015 at 8:18 am

    I think the leaves of coinvine are unifoliolate, a compound leaf with a single leaflet. (described in Isley’s Vascular Flora of Southeastern U.S., Vol3, part 2). You can sort of see this in John’s pic of the inflorescence branch (the top row of leaves). There is a “joint” on the petiole showing where the Petiolule begins.You should use this on one of your quizzes on leaf types, your students will love you for it.

    • George Rogers

      September 6, 2015 at 10:31 am

      They already loathe and despise me, so why not have some quiz-time fun? I wonder if you could make a unifoliolate leaf turn trifoliate with hormones. Where did those missing leaflets go, and why?

      • Steve

        September 13, 2015 at 7:45 am

        I smell a future article?
        Dalbergia sissoo has more leaflets, but they too have joints on the petiole, indicating that ancestors were once bipinnate.
        Pithecellobium leaf shapes are weird modified bipinnately compound leaves.

  4. George Rogers

    September 13, 2015 at 10:14 am

    That is a bag of suppressed leaflets worthy of attention and article. As I’m out and around with camera will take some macros of each—for that future article. Great idea….and useful in biology class evolution lesson to boot, because those species are on campus in our face.


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