Pesky Burrs and Extreme Macro Photography

In the park with Anthony today, I brushed up against a plant that left my arm plastered with seed pods that apparently became molecularly bonded to my shirt and skin. They were exceedingly difficult to remove. When I was actually able to pry one away, it stuck just as well to my fingers. I could feel it grabbing onto my fingerprints.

If I could then somehow flick it with enough force to propel it away from my finger, it would generally manage to land on my pant leg, which started the whole process over.

I'm not sure I've totally eradicated them from my skin/clothes, but I thought to very carefully take some in a plastic bag (about the only thing they didn't adhere to) home for some super-close-up photography.

They came in pods of four or five seeds. Here's a close up of about 1cm length of the pod...

Pesky Seeds Covered with Incredibly Tenacious Burrs -- Kyoto, Japan -- Copyright 2007 Jeffrey Eric Francis Friedl, https://regex.info/blog/
Nikon D200 + reversed Sigma 30mm f/1.4 — 1/250 sec, f/16, ISO 320, SB-800 at 1/32nd power — full exif
Pesky Seeds Covered with Incredibly Tenacious Burrs

(I spent some time researching what kind of plant they're from, but I came up empty. Peter, any ideas?)

The barbs are not visible to the naked eye, and just barely in this extreme closeup.

It's difficult to get a sense of scale, so to offer some help with that, here is a section of the hook part of the Velcro™ closure on my camera flash's pouch, at the same scale as above.

Velcro Hooks, at the Same Scale -- Kyoto, Japan -- Copyright 2007 Jeffrey Eric Francis Friedl, https://regex.info/blog/
Same setup as above, but with the SB-800 at 1/8th power into a tissue covering the target area — full exif
Velcro Hooks, at the Same Scale

I'll write more about how I took these pictures, with additional examples, another day... (UPDATE: here)


All 6 comments so far, oldest first...

There is a cactus in the Southwest US called the “Jumping Cholla” that has similar behavior. You can read about it here.
I have had experience with it and it is described by some as an “aggressive cactus.” They are right. My friend had his ski pole walking stick fitted with a rubber tip and it was taped with medical tape. He just brushed the plant and it took about 10 min. to get the doggoned thing off [scraping with a stone, not our hands. Near Phoenix AZ]
Still enjoying your blog.
Mel

— comment by Mel Lammers on October 16th, 2007 at 12:24am JST (17 years ago) comment permalink

I admire the dedication to science and botany!

I think this may be the fruit of a tick trefoil such as Desmodium illinoense, D. rigidum or D. paniculatum. All three are native to the US, but also naturalised in Japan. There are plenty of images on the web. When ripe, the pods break apart at the constrictions, each section containing a seed, all ready to be dispersed by a passing animal – or human. Clever stuff.

There are also some native Japanese species of Desmodium, but I’m not sure that any have these burry hooks. The Japanese name for the genus is nusubito-hagi zoku.

— comment by Peter on October 16th, 2007 at 1:35am JST (17 years ago) comment permalink
— comment by Zak on October 16th, 2007 at 9:37am JST (17 years ago) comment permalink

I don’t know, Zak. Jeffrey’s velcro photo is sort of mesmerizing. The one on your link, while fascinating, is also kind of creepy. 🙂

— comment by Marcina on October 16th, 2007 at 11:51am JST (17 years ago) comment permalink

I’ve been meaning to try this trick. I have a 50 1.8, I think that can be reversed too? Don’t you need to use another adapter of some kind?

— comment by Jon on October 16th, 2007 at 1:01pm JST (17 years ago) comment permalink

This is a photo of Stick-tight or Tick-trefoil, Desmodium sp.
For a list of possible species see: http://plants.usda.gov/java/profile?symbol=DECA7&photoID=meca14_001_avd.tif

— comment by Jen S on October 14th, 2011 at 4:57am JST (13 years ago) comment permalink
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