Prickly pear cacti, genus Opuntia, are easily-recognized members of the cactus family (Cactaceae) with a very wide native range across the Americas. There are more than 150 species, native from southern Canada to Argentina and Chile. They are also called nopales (singular nopal).
|Prickly pears in desert grasslands, not flowering|
|large prickly pear in Arizona|
|tree prickly pear seen in Argentina|
|Close up of flowers on "tree" prickly pear above|
They attract a variety of bees, flies, butterflies, beetles and other flower-visiting insects. Almost all prickly pears require insects to carry pollen between flowers for seed production.
|Bumble bee in prickly pear flower|
|Prickly pear fruit. On bigroot prickly pear, Opuntia|
macrorhiza, a northern speices, the fruit (tuna) is about 2" long
|Prickly pear fruits (tunas)|
The one I cut up, from the bigroot prickly pear (Opuntia macrorhiza) in my yard, looked pretty innocent but I still got the tiny irritating hairs, glocids, in my fingers from picking them. There isn't much to eat on these either. They tasted good but not wonderful.
|Here is the fruit cut open. |
Blade of a small paring knife.
The fruits contain ten to over a hundred seeds, depending on the species. Taken directly out of the fruit, the seeds are notoriously slow to germinate. Passing through an animal improves germination, so treatment to breakdown the hard seed coat helps germination. Looking online, some of the websites used southwestern or Mexican desert prickly pears, likely cultivated varieties, and recommended solely to keep the conditions warm enough (SFGate) while others not only treated the seeds with acid but then refrigerated them for months (imitating winter) (link). If you gather tunas and want to germinate seeds--seedlings are very cute!--try to provide conditions similar to those the seed would experience where the adult plant was growing.
|prickly pear (Opuntia) seeds|
Prickly pear cacti are widespread plants, avoided because of their spines but both the cladodes (see previous post link) and fruits are edible. The flowers are beautiful and pollinators love them.
And, you can put the spines to work for you. This very happy prickly pear was planted on the corner of a corner yard near me and it is very effective keeping pedestrians on the sidewalk.
Comments and corrections welcome.
Lots of information on particular prickly pear (Opuntia) species on U.S. Forest Service data base, for example: link (google genus and species, chose Forest Service FEIS options)
Reyes-Agúero, J. A., J.R. Aguirre R. and A. Valiente-Banuet. 2006. Reproductive biology of Opuntia: a review. Journal of Arid Environments. 64: 549-585.
Kathy Keeler, A Wandering Botanist
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