Sep 21 2013

Spanish Needles

Published by at 7:00 am under Plants

Spanish needles in bloom (photo by Kate St. John)

These small yellow flowers look innocent, but after they’re fertilized the central disk grows longer and develops into hard, brown seeds.


The seeds splay out as they dry. Each one is topped by a tiny pitchfork of two to four spikes with downward-facing barbs.

Sanish needles gone to seed (photo by Kate St. John)

The needle-like seeds detach easily from the plant…


… and stick to my sweater.

Spanish needles on my sweater (photo by Kate St. John)

That’s when I noticed the plant.


The Spanish Needles plant (Bidens bipinnata) is so annoying I was sure it was an alien invasive.  Not!  It’s a native annual that’s very adaptable, willing to grow in disturbed soil in vacant lots.  These seeds grabbed me on Winthrop Street in Oakland.

Bidens bipinnata has many hitchhiker relatives in the Bidens genus.  I identified this one by its lobed leaves and needle-like seeds.


(photos by Kate St. John)

3 responses so far

3 Responses to “Spanish Needles”

  1. John P. Englishon 21 Sep 2013 at 10:56 am

    Lots of these down in Duck Hollow on Thursday. I successfully avoided being stuck or otherwise impaled 🙂

  2. kcon 23 Sep 2013 at 10:11 am

    I’ve seen goldfinches eating these seeds.

  3. Furry Gnomeon 12 Oct 2013 at 7:39 am

    Don’t recall seeing that one; I’ll have to watch for it. I was planning a post on fall burs too, if I ever get my computer back!

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