Nomaphila corymbosa is the name under which Blume described the species in 1826; today it is called Hygrophila corymbosa.12 It is native to Myanmar, Thailand, Laos, Cambodia and the Philippines and introduced in Florida and north-eastern Mexico.2
Stalked leaves are arranged in decussate pairs on upright, branching stems, and the two-lipped flowers are pale blue to blue-violet.1 Several genetically stable forms with markedly different leaves are cultivated.1 Two sites on Sulawesi have been described: wet ground with a purely emersed, broad-leaved form, and a fast-flowing small river in which a narrow-leaved form grew partly below and partly above the water.1 In the aquarium it grows quickly; a small, staggered group in the midground or background is recommended.1
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