Gratiola viscidula Sticky Hedgehyssop

Gratiola viscidula is a rare aquatic plant native to the eastern United States, found in seepage bogs, pond margins, and clear streams with very soft, acidic water. In aquariums it is a specialist plant requiring precise water chemistry — soft, acidic conditions with strong CO2 injection and high light — to thrive. When conditions are met it grows as a compact, low stem plant with small, toothed, textured leaves in an attractive olive-green tone. It is sought after by experienced aquascapers and collectors interested in rare North American native aquatic flora.

Light: High (70–100 PAR); strong light required for compact internode growth. CO2: Required at 25–40 mg/L; without CO2 growth stalls rapidly in this demanding species. Fertiliser: Comprehensive micronutrient programme; low KH and GH water essential. Planting: Midground groups of 3–5 stems in nutrient-rich soft substrate; trim every 3 weeks. Growth: Slow; 10–20 cm; demanding species suited to experienced planted tank keepers.