Another Epiphytic Orchid - from Kangaroo Valley

Geography means everything - if you are an Orchid.
The first of these Orchids are found less than 8 Km from my house, in Robertson. But they might as well be 1000 miles away. They grow in the Upper Kangaroo Valley, in the River Sheoaks which line the streams there.

This one is Dendrobium (Dockrillia) linguiformis (which means tongue-shaped). That refers to the leaf shape. The flowers are long and "spidery", and quite showy, relative to the small-flowered Dendrobium striolatum which I showed recently, growing on rocks along the edges of the escarpment.
We do not get Sheoaks up here on the basalt caps. Nor do we have slow-running rivers, winding along through flat sandstone valley bottoms. But the creeks which feed the Kangaroo River start on properties like mine, here in Robertson - just 8 Km away, but some 500 metres above.

So, while we get Sarcochilus falcatus, and some other Dendrobium (Dockrillia) species, we do not get these ones. These two photos were taken in mid-August last year - so the timing of this post is apposite.Another related plant is the appallingly named Rat's-tail Orchid, Denrobium (Dockrillia) teretifolia. Its Latin name refer to the rounded shape ("terete" - in cross-section) of its leaves.
These are also growing on Sheoaks - in fact dead Sheoaks in many cases - right on the edge of Jervis Bay - which is on the coast, south from Nowra. That is about 80 Km away from Robertson, by road. This next photo was taken in late August last year.I could not get close to these plants to photograph them, which is good, because it means other people could not get close to them easily - to steal the plants. Their flowers are very similar to the related species (above). But their leaves are more than 30cm long - long and thin.

Many epiphytic Orchids appear to have a liking for Sheoaks as host plants. In the case of these two species, the roots of the Orchids appear to grow into the bark of the host trees. In the case of dead sheoaks, the old bark lifts and cracks, and that actually suits the Orchids, which can grow their roots right in under the bark, where the roots are protected. By contrast, the Sarchochilus I showed last week lives amongst the dense coating of Rock Felt Ferns, which help trap moisture from the mist and rain of Robertson.