Hygrophila guianensis

The classification of the name Hygrophila guianensis is disputed: aquarium literature and identification aids treat it as a synonym of the variable American Hygrophila costata, which is also traded under this name.¹²³ In the current global botanical checklist, however, H. guianensis is a separate species that occurs from south-eastern Mexico to southern tropical America and grows as a subshrub.⁴

Whether plants traded as guianensis really belong to H. costata is not certain. ^{H. costata” – Flowgrow forum (accessed 5 October 2026)">5} True H. costata is easy to grow emersed and then often produces flowers and fruits; in the aquarium, by contrast, it grows very slowly even under optimal conditions and is therefore only moderately suitable.¹ Soft water, a nutritious substrate and plenty of light provide good conditions.¹

1. Kasselmann, C. (2019): Aquarienpflanzen. 4th edition (German). - Ulmer Verlag, Stuttgart: p. 384.
2. Hygrophila costata – Flowgrow aquatic plant database (accessed 5 October 2026)
3. Hygrophila – Aquarium and Pond Plants of the World, idtools.org (accessed 5 October 2026)
4. Hygrophila guianensis – Plants of the World Online, Royal Botanic Gardens Kew (WCVP data as of 4 June 2026, accessed 5 October 2026)
5. Thread “Hygrophila "angustifolia" von Tropica => H. costata” – Flowgrow forum (accessed 5 October 2026)