Den/Dockrillia cucumerinum culture

[SaraJean]

Originally Posted by Roberta

I wonder if it wants cooler nights

Originally Posted by estación seca

I don't know what are its summer night temperatures in habitat.

That definitely might be the problem. My typical night temps July-September are usually in the low to mid 80’s, with the heat index being much higher since humidity is about 80-95% once the sun goes down

Looks like I’ll try to find a nice dry, dead area to cut off a piece and try it potted, or on a modified horizontal mount, indoors

[estación seca]

If it's that hot and wet there at night, I think summer night heat is the problem. Almost all succulents have severe trouble respiring when summer nights are above about 85 F. Any chance you could bring this into the house during the summer?

[ArronOB]

If it makes you feel any better, my friend who is a native orchid enthusiast grows all other species of local epiphyte well, but struggles with this one and currently has one of his two plants dying.

We are towards the southern limit of its range but it’s a fairly widespread species so must be able to adapt to a variety of temperatures. Ditto rainfall patterns, in fact it is here in a zone of winter max rainfall with dry summers but in the north of its range it is summer rainfall max, bordering on monsoonal.

I think my friend has tried everything culture-wise, none of which seems to make a difference once the decline starts so it leaves me wondering if the plant is lacking something in cultivation like a beneficial fungus or a chemical produced by the host tree (if such a thing exists).

I have never seen this orchid in the wild but apparently it’s preferred habitat is along watercourses, in river oak trees. River oaks are casuarinas. There are several orchids that are hosted by casuarinas and will grow on nothing else, even when the casuarinas are only a very minor part of the flora. The local example is Dockrilla teretifolia. Makes me wonder what is different about a casuarina - what it provides that cannot be obtained from any other tree.

I know there are other Dockrillas that will only grow on specific forest trees. Dockrilla aemulum will only grow on ironbark, except for one subspecies which will only grow on brush box. Walking through the forest, there is nothing obvious about either host species which sets it apart.

PS. I said ‘will only grow on’ a few times. There may be records of them on other species, just very rarely and never in my experience.