I was lucky enough to score a piece of this Crypt from a local shop display tank. I normally use small 95mm square pots for my crypts but this was a big crypt so it went in a 150mm pot and is in a 600l 6x2x2 tank (sharing with some purple spotted gudgeons). Its a big crypt - currently 40cm tall and the biggest leaf blades are 20x7cm excluding the petiole. A few sellers in Australia recently have been selling a Crypt cordata named "Red Giant" so I'm assuming this is the same - the undersides of the leaves are very red. There are a few other similar plants in Australia at the moment: A Crypt cordata distributed by Dennerle, and another Dennerle variety sold as Crypt. x purpurea but clearly both are varieties of
Crypt cordata var. siamensis.
"To make a long story short: almost all Cryptocoryne cordata plants in our aquaria today belong to var. siamensis. If you have it growing successfully in your aquarium there is a more than 90% chance that it is var. siamensis. And even if it is not growing well, there is probably still a more than a 90% chance that it is var. siamensis. If it were one of the other varieties of Cryptocoryne cordata it would most likely be dead by now. Of course, if you are one of the few people keeping aquaria with a pH of 4 – 5, you may have something else, but even then there is a good chance that you may have var. siamensis."Jacobsen, N., and Bastmeijer, J.D. 2014. On Cryptocoryne cordata var. siamensis. Aquatic Gardener 27(3): 29–39.
