So, that is what they are called! I have them growing wild in my garden, they reseed readily. They are a kind of daikon. They get 3-4 feet tall and start blooming. The root is small and hard and totally inedible. It is hard to even cut the root. They don't really need a support they stand up by themselves. The flowers are held high up and are fairly open so unless the winds are kicking up more than the usual trades they hardly notice. They have a little bitter bite and Filipinos make a salad with them.
Happy gardening in Hawaii. Gardens are where people grow.