Dendrobium hellwigianum is a high-altitude species from New Guinea and is reputed to be difficult to grow. I have no difficulty growing it or flowering it with cool temperatures and high humidity. It is an attractive plant with thick, narrow leaves that look a bit like chives to me and the unusually colored flowers come in pairs among the leaves and at the top of the pseudobulbs. The plant is 10cm tall and the flowers 3cm. I grow the plant mounted on a small slab of cedar with a pad of moss around the roots of the plant.