Zanthoxylum simulans

Zanthoxylum simulans

Zanthoxylum simulans photo credit: S. Keitch

When all of the deciduous trees drop their leaves in the fall we get the opportunity to admire the bareness of a landscape.  There is something very pure about observing the structure of a tree, the sprawling nature of its branches, with the overall stature contrasting against the gray sky.   In the winter, however, after a beautiful snow, we also look downwards. Silhouettes of smaller trees and shrubs become apparent against a pristine white backdrop.  Today, I was walking past the fraternity houses, admiring the spectacular Hamamelis display, when I saw the outline of Zanthoxylum simulans.  The lateral spines weren’t exactly welcoming, but they were certainly captivating.  I commonly see our native species, Zanthoxylum americanum or flatspine prickly-ash at arboreta, but this specimen deserves more attention.

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The formidable thorns of flatspine prickly-ash. photo credit: S. Keitch

If you’re like me and don’t like people poking around your garden, then the flatspine prickly-ash isn’t just a beautiful small tree, but a functional addition to your strategic home defense plan.  The thorns may reach an impressive size of three quarters of an inch, large enough to be a visual deterrent.  Other possible plants to bolster your living barrier include the hardy orange, Poncirus trifoliata, the wintergreen barberry, Berberis julianae, or the Devil’s walking stick, Aralia spinosa.


Multiple lead trunk of Zanthoxylum simulans. photo credit: S. Keitch

All kidding aside, the overall form of Zanthoxylum simulans is graceful, with its multiple lead trunks striving upwards of fifteen feet. I slightly favor the finer branches because the thorns appear even more pronounced.

As a member of the citrus family, or Rutaceae, flatspine prickly-ash possesses a common citrus family characteristic of aromatic foliage when crushed.  The compound foliage is a lustrous green tone that complements the inflorescences, which turn a beautiful pinkish-red in the late summer.  However, it is the fruit, namely the pericarp, which is sought in Asia for its medicinal and flavoring properties.  The common names including the word ‘pepper’ are derived from the culinary use of the dried fruits as seasoning herbs, described as more pungent than black pepper.

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Close-up of the surly nature of Zanthoxylum simulans. photo credit: S. Keitch

If you want to try something a little bit different, I would recommend any of the Zanthoxylum species. They are an interesting specimen for tough conditions.  Of course, I must warn you of their surly nature and to be mindful of where they are located.  During my first encounter with Zanthoxylum simulans, I was left with a painful impression that I will never forget.

Zanthoxylum simulans

Sam Keitch
  • Drew Peogn
    Posted at 12:48h, 23 February Reply

    Since the first time I saw our native tree Zanthoxylum americanum, the Toothache Tree, and learned its name, it’s been very memorable.

    Z. simulans might have more impressive thorns, but the Toothache Tree has that uncomfortable association dentists might not appreciate between its name and what you imagine the kind of pain those thorns could inflict. Actually, Native Americans chewed the bark and berries to relieve toothache pain, but the tree’s naked branches definitely have a certain sadomasochistic appeal!

  • shoshonnaray
    Posted at 07:27h, 19 June Reply

    In the south we call it Tickle Tongue

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