What a wonderful show we have in the greenhouse. Today would have been set up day for the London RHS Orchid Show, and I know several students who will be gutted today, not being there – me too. We will just have to make the 2021 show the best ever.
One species that would have had a big reaction from Show visitors is this dramatic species from the Himalayas.
Dendrobium densiflorum has to be one of the most dramatic orchids we grow, and we have been fortunate to see it flowering its natural habitat too. In Sikkim the species grows at around 1000m where it lives as an epiphyte generally in tall semi-evergreen trees with little moss as shown below. The high end of its range overlaps the lower end of Dendrobium nobile’s range and we have seen both species flowering together during April just as they do in our greenhouse,
We grow out plants mounted with heavy watering in the summer. This is one of the plants that section hops in the greenhouse to replicate its natural habitat. In the summer it grows its new pseudobulbs rapidly and we find it a home in Warm Asia where heat and heavy watering help it to grow long bulbs. Its native Sikkim becomes quite cool at 1000m in winter and so we move it for a fairly dry rest in Coll Asia from November until February. We then move it back to warm where the change in climate usually induces rapid flower development, taking about six weeks after the move.
Plants are very long lived and flower from older pseudobulbs so patience is required to grow a specimen – but it is well worth it.
This is, of course, the type specimen of Dendrobium section, densiflorum and it is interesting to contrast it with its very close relatives, also flowering in the greenhouse this week.
Her is D. dendiflorum with D. thyrsifloum – Dendiflorum doesn’t have much denser flower racemes but the plants are distinct apart from the obvious colour difference. Densiflorum has shorter, square sectioned bulbs, while thyrsiflorum has longer round sectioned bulbs. Dendrobium lindleyi (bellow) is much smaller than either densiflorum or thyrsiflorum.
Then there is Dendrobium chrysotoxum, (below) with much stouter bulbs and a much looser flower raceme.
What a great group of orchids.