As usual, I had the great fortune to be brought though a maze of complex roads to this remote river in Pahang near Bukit Ibam area by my explorer friend where he found cryptocoryne with spathes with bright yellow bullate wide limbs and raised collar. He termed them as C. sp. 'Yellow Ring' first, leaving it to the experts to conclude whether they are new species, hybrid or just another variety.
From what I saw, all the specimens were in submersed form. The base of the river was sandy.
The leaves were greenish on the upper side with some faint markings and slightly reddish on the under side, nothing really spectacular.
However, the spathe is so beautiful and striking that I will leave you to enjoy the below photographs by yourself and ponder over what they should be.