Well, the stress explanation certainly sounds reasonable, anyway. The bloom in question was literally at the end of a vine that's at least twelve feet long, and everything (leaves and buds) beyond it has withered and died. The entire vine seems to be concentrating on seed pod production and ripening now, so I guess the 'Blue Square' was probably just the result of "starving out" at the end of the line. Still, the pod's been tagged, and is developing seeds, so I'll see what grows from it, if only another normal 'Blue Star' vine.
This entire set is sort of an experiment in random hybridizing and cross-pollination, anyway. I was mainly concerned with growing a shade barrier to shield me from sun and neighbors, so I planted a bunch of different varieties in the hopes that at least some would like the marginal conditions and cramped space that I had them in. When I started getting flowers, I began hand-pollinating them with a Q-tip, without any regard to differentiating between the types. I've got 'Blue Star' (from a packet labeled as "Flying Saucers"), 'Milky Way', 'Star of Yelta', 'Picotee Red', 'Picotee Blue', 'Scarlett O'Hara' (supposedly), and 'Candy Pink' varieties, all sharing space and pollen with each other, and being randomly dusted by hand, based on what happens to be blooming on the same day, and what's hanging on the end of the Q-tip from previous days. All of them came from garden variety (ahem) seed packets from the hardware store, so I figure I'm not wasting or endangering any rare or exotic seed stock in order to entertain my curiosity.
For what it's worth, the 'Star of Yelta' vines did exceptionally well in lousy growing conditions and cramped space, with weeks on end of enthusiastic blooms, most of which seem to have made seed pods (I now have hundreds of "mostly Star of Yelta" seeds).
The 'Milky Way' vines came along next, with lots of blooms that are now providing ripe seed pods.
I went on vacation in the beginning of August, and had to leave the plants in the care of an automatic watering system that I didn't have time to calibrate properly, so even though the plants survived, they seem to have been stressed enough that it changed the "balance of power" once again, and when I came back, I was getting lots and lots of 'Blue Star' blooms, the seed pods of which are progressing well.
All throughout the process, I've had random sightings of the 'Picotee Red', 'Candy Pink', 'Scarlett O'hara', and 'Picotee Blue' flowers, all of which have been wantonly dusted with anything else that happens to be open that morning.
It's been an interesting learning experience, and even though my random and scatter-shot methods are no doubt making some of the Morning Glory connoisseurs cringe, I've been having fun with it, and will be interested to see if any of the plants produced by these seeds are blatantly different from any of the varieties that I started with.
