False Acacia – Robinia Pseudoacacia

robinia pseudoacacia

You might know it is the black locust tree, but here in the UK it is the false Acacia because it looks like an acacia, but lacks the thorns. The leaves are very different from anything else growing here, with bright yellow-green leaves. Everything else is green-green.

This Robinia pseudoacacia is in the park just 150 yards from where we live, and because it is young, the racemes are hanging down low so I could get a good look at them. I also saw a pod from last year’s growth, which together with the flowers says that this is in the pea family.

The Robinia pseudoacacia was introduced to Britain from the New World in the 1600s, and this being a university town, and the parks originally belonging to the Colleges, I wonder who planted the bigger trees? I will have to take a look at the big specimens to see their girth, which will tell me how old they are.

robinia pseudoacacia cloesup showing the racemes


  1. Joan E. Miller says:

    What synchronicity! Today there was a post on my FB gardeners group, asking to ID that very tree! I grew up around locust trees, honey locusts in Teaneck, that dropped large long seed pods. The wood is very hard, if you ever try to chop it!

    Liked by 1 person

  2. Strange, the Black Locust here most distinctly have thorns (and wicked ones at that :/ )
    This year they had the most incredible blossoming I’ve ever witnessed…
    Will send you a shot.


    1. Aha, so maybe Black Locust is not correct, but Wikipedia thinks it is the same tree. I got your photo, and the flowers look very much the same as on the tree I saw.


      1. Yes, they are definitely the same flowers, aren’t they? I’m thinking that the info on “thornless or not” is actually where the error lies… There is an ornamental version called a ‘Honey Locust’ – not sure of the reasoning as they have no flowers, no seed pods (and no thorns, lol)
        I’ll go out in a bit and snag you a photo of them as well… (Wickedly impressive!)


        1. I looked up a couple of sources that say ‘Robinia pseudoacacia (black locust) and Gleditsia triacanthos (honey locust)’ and that black locusts have thorns. That doesn’t make sense at all to me because Robinia pseudoacacia definitely does not have thorns.

          The weak point in this pyramid of logic is yours truly. So I shall go and carefully look at the specimens near here. If I have to revise my views it will undo years of learning 🙂

          Liked by 1 person

        2. Haha! Well, as my grandmother liked to say: it’s always a good day when you learn something new!


  3. Today I took a look at two Robinia pseudoacacia trees in the Botanic Gardens here in Cambridge, and definately no thorns.


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