Gratiola viscidula
Alternate Names:
Short’s Hedgehyssop, Hedge Hyssop, Small Water Speedwell, Sticky Hedgehyssop
A unique native plant with triangular leaves, capable of growing swirly carpets and attached to hardscape like moss.
Care At-A-Glance
Appearance: Very unique light-green triangular leaves that look great as a carpet or foreground bush.
Difficulty: Easy to Moderate
Size: Seldom taller than 5 cm. Usually shorter than 2cm
Native Range: Southeastern United States (first found in the Carolinas)
Position and Use: Carpet to bushy foreground ‘hedge’. Epiphytic: attaches to rocks, driftwood, and other hardscape much like moss. Makes a great plant for aquarium "Bonzai" trees. Regular pruning causes side shoots to proliferate and the plant will become bushier until it eventually crawls along the substrate.
Growth Habit: Stem plant with short internodes
Growth Rate: CO2 - Moderate to fast/ No CO2 -slow
Lighting: 2/5 - 5/5
CO2 Requirements: Natural habitat CO2 concentrations range from 13-20ppm - which is higher than in most aquariums where levels can reach as low as 0.1ppm. CO2 injection is thus highly recommended. Even DIY CO2 will enable much better growth. Gratiola viscidula does not appear to be able to use bicarbonate effectively and will have a difficult time with no CO2 supplementation. It is a very easy plant to grow in tanks with even a small amount of additional CO2.
Water Conditions: Highly adaptable, but prefers soft and slightly acidic to neutral (pH of 6 - 7). Temperatures from 55-85F. Suitable in cold-water tanks containing goldfish or native fish. Does appreciate clean, mechanically filtered water so its fine leaves do not get blocked.
Substrate: Not picky but benefits tremendously from a rich substrate when planted - especially helpful when growing dense carpet. Its shallow roots do not require deep substrate depth. When grown on hardscape, Gratiola v. seems to absorb a lot of nutrition through roots suspended in water. It can even be grown on the surface of rocks like moss.
Propagation: Stem Division: Each internode can theoretically regenerate a whole plant though we recommend at least 4 -5 sections
Specific Considerations: Can be grown like moss attached to surfaces such as driftwood or rocks with string or superglue. It will eventually anchor itself on surfaces so attachment does not have to be permanent.
Emersed Growth: Can be grown emersed or partially emersed in terrariums/paludariums. The emersed form is more compact and robust than its featherier submerged form and feels more substantial to the touch. Will flower when grown out-of-water. Requires humidity typical of terrarium plants.
Detailed Information
General Information and Natural History
Native primarily to the Southeast United States, Gratiola viscidula is common in wetlands, marshes, swamps, and along the margins and shallows of permanent freshwater bodies. It is a native wildflower that has become a relatively new but very welcome addition to the aquarium hobby. It is both low-growing and robust, with a distinctive "thorny" appearance that sets it apart.
In its emersed (or non-aquatic) form, It is a relatively small plant, usually growing to heights between 6 to 12 inches (15 to 30 cm). It has alternate leaves that are typically lance-shaped, glossy, and medium grass green. It produces small, tubular flowers ranging from white to lavender and blooms from spring to early summer. You will see this kind of growth in a terrarium.
References and Further Reading
1. Spooner, D. (1984). Infraspecific variation in Gratiola viscidula Pennell (Scrophulariaceae). Rhodora, 86, 79-87.
2. Baskin, J., Baskin, C., & Spooner, D. (1989). Role of temperature, light, and date on germination of four wetland perennials. Aquatic Botany, 35, 387-394. DOI: 10.1016/0304-3770(89)90009-0.
3. Polukonova, N., Navolokin, N., Raikova, S., Masliakova, G. N., Bucharskaia, A. B., Durnova, N., & Shub, G. (2015). [Anti-inflammatory, antipyretic, and antimicrobial activity of flavonoid-containing extract of Gratiola officinalis L.]. Eksperimental'naia i klinicheskaia farmakologiia, 78(1), 34-8. Link
4. Estes, D., & Small, R. (2007). TWO NEW SPECIES OF GRATIOLA (PLANTAGINACEAE) FROM EASTERN NORTH AMERICA AND AN UPDATED CIRCUMSCRIPTION FOR GRATIOLA NEGLECTA. Journal of the Botanical Research Institute of Texas, 1, 149-170. Link
5. Stuppner, H., & Müller, E. (1994). Structure revision of gratioside. Phytochemistry, 37(5), 1483-5. DOI: 10.1016/S0031-9422(00)90439-4. Link
6. Zia‐ul‐Haq, M., Kausar, A., Shahid, S. A., Qayum, M., Ahmad, S., & Khan, I. (2012). Phytopharmacological profile of *Gratiola