Sunday, April 13, 2008

Cactaceae (It's Latin to Me!)

I was putzing around in the yard the other day and discovered something I had not seen before, cactus seed pods. Excuse me, ovaries. I don't know how I thought cactus multiplied -- I guess I just figured they budded from the ground, sort of like irises do, from tubers or something.  I hollered to Alison the Curious, and we sort of dissected one.  Here is what we found:

This was a great botany mini-lesson for my kids, and for me, too! This variety of beavertail prickly pear cactus does not bear edible fruit.  Its fruit is more like a casing full of seeds, with no pulp. A fruit is a pregnant flower. If the fruit were edible, these seeds would be encased in pulp, similar to an apple or a tomato.   We saw the pollen and the stamen, plus the floral tube of the cactus flower, all of which grow out of the ovary.  We learned how the pollen travels down the floral tube and joins with an ovum (egg cell)in the ovary to make seeds, or cactus babies. This plant may produce a million seeds in its long lifetime, but only one or two of them will live long enough to become a new plant.  Sometimes a cactus stem will break off, and if it lands just right, under the right conditions, it will take root and grow.

The little clusters of spines that you see in the photo to the right, above, are called glochids.  These spines are very fine, very small, and very difficult to remove without knowing a few tricks.  Alison got her hands full of them, but Elmer's glue pulls them out easily if you spread it on and let it dry, then peel off. (File that helpful tip away for your next family vacation to the desert.)

Below you can see a bud, then the flower, and on the right, the dead, dried up blooms sitting atop their ovaries. In a while, these dead blooms will look like the seed pod (no, ovary) in the top photo. These beautiful flowers last just a couple of days, and the whole plant only blossoms for a week or two.  God designed it this way to conserve water lost by evaporation through the soft petals.  (He knows what he is doing. )

We have a long, thick row of these beautiful cacti growing along the west side of our home.  I wish I had a photo for you -- about a week ago they were all in full bloom and oh, so pretty!  (I'll have to check with the resident plant photographer, Booklover/Amy, to see if she has one.)  The blooming desert is a brief but beautiful reminder that there is life this barren wilderness, after all.

I hope you enjoyed our lesson -- we did!



  1. Nice Botany lesson. I guess I had never thought about how baby catus formed - not like any would survive here anyways. Plants that poke & sting aren't at the top of my list (not even roses). Nice tomatoes too. Is that an ever-bearing plant or do they just ripen now and that is it?

  2. ByHisGraceInColoradoApril 17, 2008 at 7:24 AM

    I can't wait to show the kids. BTW, I commented on your comment over on the porch :)


  3. That is quite interesting! I love that kind of "school" we seem to learn so much more that way.



  4. I'm sorry I started to tell you that if this was a Prickly Pear cacti that they make the most wonderful jam but then I realized that you have a Beavertail so no fruit and no jam :( so that is why I deleted my first comment. Gorgeous pictures and I enjoyed your blog.




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