Dahlia imperialis?

Well, I guess nobody knows exactly what Dahlia this is, now blooming at the UC Botanical Garden, but D imperialis is close. I have often heard people call it Thanksgiving Dahlia or Christmas Dahlia because it blooms this time of year. The flowers may be pink or white, single or double, but his plant is TALL. Eight to Twenty Feet Tall! It grows easily in this area; all it takes is putting a section of the stem (which looks like bamboo) in the soil. It takes at least a year to get to blooming size, but then they take care of themselves. Some support can be nice, and they don't like a hot, dry location, so next to a fence might be good. Very easy and has beautiful flowers at a time of year when not much is blooming. A great addition to a bay area garden.