One of our most spectacular winter-flowering trees is the Chinese sassafras. Sassafras tzumu (pronounced Zoomo). It can eventually reach 100′ tall in the wild, but we rarely see this exceed 35′ in cultivation. The clusters of bright yellow flowers adorn the plant, starting for us in mid-February, providing a welcome feast for honeybees when the temperatures allow. These rarely seed in cultivation, but we were fortunate to obtain a seedling a few years back when the large specimen at the JC Raulston Arboretum set seed.
It certainly is a fantastic tree. I planted one in my garden last year and it grew a lot in just one season.