In this same stream where C. sp. 'Lingga 7' and C. sp. 'Lingga 8' were found. We found another patch of cryptocoryne further upstream which looked rather different in terms of the colour of the leaves.
As we could not ascertain whether they are the same as C. sp. 'Lingga 7 / 8' as no spathe was found, my explorer friend decided to term it as C. sp. 'Lingga 21' first until we are able to determine the species identity in the future. Below are some photographs of a few specimens collected.