orange form of the Prickly Pear Cacti flower
the more common yellow form of the Prickly Pear Cacti
Here's an interesting question to the botanists in the group. Why does the Prickly Pear Cacti sometimes produce orange flowers instead of the more standard yellow?
There are many possible answers: differences in soil, differences in genetics, differences in age. While each might be a good answer, logic and observation would tell us that each proffered reason doesn't make sense. If the variation was due to soil, then all of the cacti in the one clump should exhibit the same colour. If it was genetic, then again, the cacti in a group should all be showing the same characteristics (most cacti reproduction is from budding - or so I believe). Finally, if colour were age dependent then there should be a whole lot more orange cacti, or at least as many as the age distribution would suggest.
No, there is something much more interesting going on in the world of the cacti. I offer up the question to some bright young mind heading off for an interesting stint of studentism at our beloved Thompson Rivers University.
Or, if one of you kind readers know what is going on, please feel free to comment and let us all know.
P.S. John Foster wrote: In the Genus Acer, the variation in the colour of fall leaves has to do with sugar, moisture and pigment content. I just read that one explanation for variation in Opuntia flower colour also has to do with moisture and sugar content. If flowering is asynchronous, then indeed moisture, and sugar content would influence colour.