First, thank you saltcedar, you were partially right. Google saved the day. I typed in what I can remember about it, "yellow flower, Vietnamese New Year plant, pluck leaves to force flower to bloom, etc..." and BAM, I got my answer. It's a Bong Mai, or a Hoa Mai, or scientifically, Ochna serrulata (South Africa) or Ochna integerrima (Vietnam). It's also called a Mickey Mouse plant. Judging by the leaves and bark on mine, my mystery plant looks more like Ochna serrulata (South Africa). Finally, I can sleep well at night. LOL! I hate it when I have plants with no name. Here is a link that might be useful: Plants o Hawaii - Ochna serrulata (Mickey Mouse plant)

Marcelo, Yes, there are at least 3 varieties of Tabebuia that do quite well here in the San Francisco Bay Area. T. chrysotricha is in full bloom right now, I have several planted out here in the Berkeley hills in full bloom right now, and also one right on the bay in Alameda, which is not as far along, but also budded up with flowers. T. impetiginosa, lavender flowered is also grown here, and is known to repeat bloom after the first spring flush. This is less commonly planted out, but both these species grow and bloom here, and will easily handle our normal temperature range, and can also be grown in the inland valley areas such as Walnut Creek, (there are very floriferous mature trees of both at the Ruth Bancroft Garden). There is also a hybrid of these two species, more commonly seen in SoCal. I would have to admit that they flower even more profusely where spring is warmer and there is more accumulated heat, so that I generally try to plant these in protected courtyards or against south/west facing buildings for best bloom. They are unusual enough here in the SF Bay Area that most people don't know them, I love the taste of the tropics they bring to a spring garden here in Berkeley. We also have Hymenosporum flavum in full bloom here, and a Delostoma roseum tree in a client's garden is so fully budded up that the next couple of weeks should be spectacular,(this one blooms nearly all year round for me). Of course, the Brugmansia 'Charles Grimaldi' are so loaded with flowers right now that it seems more like summer than spring, and the trees can be 15 feet tall here. Charles Grimaldi never is out of bloom in my own garden, even in January.

Yeah, I wonder what the latin name for this tree is. When I was in Vietnam I can't help but notice how all those potted Mai all a sudden begin their bloom cycles a few days before the lunar New Year. And when Vietnam biggest holiday comes rolling by, they are just choked with all those bright, exotic yellows from the flowers. One of my relative had a big potted one that had almost no leaves. Then he watered it and all a sudden new buds began to form, followed by the leaves and the flowers.

I have some ochna integerrima in one gallon container. I like to trade for lithops or desert roses. I already have red and pink. I will consider other colors.