Steve, It is writen that it is a fragant specie but I couldn't smell anything. Maybe because the flowers have just opened or maybe because the plant is just next to D. chrysotoxum who is very fragant...
In fact, I do worry a bit because this specie is a cool growing one and in Bangkok it is not that type of environment. But we will see because I do have other species who are said to be cool growing and blomm well here...
Den. wardianum is cool growing one and you need condition close to nobile to do well. I find it Den.findayanum and pendulum are more forgiving in culture and blooms well under intermediate condition.