Tonina sp. 'Belém' is the trade name under which a Japanese company introduced the plant now listed as Syngonanthus macrocaulon.12 The name refers to Belém in Brazil, near which it grew in very soft blackwater.1 A herbarium comparison of its habit supports the assignment, although flowers and fruits remained unexamined; S. macrocaulon is now treated as a synonym of S. anomalus from tropical South America.35
Its narrow, light green leaves are densely set with downward-pointing tips, and the stem plant branches profusely at the shoot tip.5 It is one of the most difficult aquarium plants and requires soft, acidic water, very strong light and CO₂ as well as sufficient iron; the uppermost approx. 4 cm of a shoot serve as cuttings.15 In the forum several aquarists report very slow growth, and one also smaller leaf heads than in S. cf. inundatus.4
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