Unfortunately not all of us are on Facebook, so I wanted to post some of my photos and comments also here.
Hydnophytum mamberamoense, one of the most interesting Rubiaceae ant plants species in terms of systematics and first descriptions. As yet regarded as Hydnophytum species, but already in the "The tuberous epiphytes of the Rubiaceae 7: a revision of the genus Hydnophytum" by M. Jebb and C. Huxley has been suggested, that due to few atypical features “the species is placed in Hydnophytum more by default than by diagnosis”.
Andreas Wistuba who found it in the wild, discovered that there are large differences between specimens observed by him and the best known herbarium specimen by Docters van Leeuwen 9540 from 1926.
I contacted Rosemary Wise, who drew pictures in the above revision of Hydnophytum and asked her on what materials she based it on while working on the drawings of H. mamberamoense. She wrote that she probably rehydrated the flower from herbarium specimen as she never makes drawings based on any descriptions. When my young plant started to flower I took some pictures. Not the best ones, but it will take too much time before I will repeat them, so I wish to share them with our group.
Even if a rehydrated flower would be less precise than a fresh one, I am very doubtful if this could cause such large differences in general shape of flower and petals profile. You can compare my pictures with Rosemary Wise's drawings.
The leaves are identical as in Docters van Leeuwen 9540, but according to it and to the description of the species shoots can reach 50 cm long. As you can see on habitat pictures by Andreas Wistuba, the population found by him looks like Myrmecodia.
I have a few hypotheses in my head. I think it can be a surprising mutation within one species, that gives 1 population long stems and the second very compact. Or these are 2 different species, that have completely by accident almost identical leaves. That is why I wanted to be sure if the drawing of the cross section from "The tuberous epiphytes of the Rubiaceae 7: a revision of the genus Hydnophytum" is correct or could it be simplified. Different flowers would mean different species.
Andreas Wistuba regards this species as potentially representative of the new genus of Rubiacea ant plants. I know that some other botanists have other points of view and some research is planned.