Cryptocoryne isae usually has fewer than 10 upright leaves to 25 cm long, with a green, narrowly ovate, somewhat spongy blade, which could resemble C. zaidiana; the c. 6 cm long spathe has a short, forward obliquely twisted, purple limb with an indistinct, darker collar, whereas C. zaidiana has a long-tubed spathe with a broad, white, rugose limb and a purple throat. Its chromosome number of 2n = 10 has hitherto not been recorded for Cryptocoryne.
