Hydrocotyle verticillata
Hydrocotyle verticillata (Crawling Pennywort, Whorled Pennywort, Whorled Marsh Pennywort, Shield Pennywort)
A beautiful and extremely versatile plant that hails from temperate habitats in both South and North America.
Hydrocotyle verticillata is a fantastic low growing plant that grows along the bottom of your aquarium with its creeping "caulome", occasionally sending out round leaves on short, vertical petioles that look like underwater Lily pads. These leaves, about an inch in diameter provide a convenient and very cute perch for bottom dwelling fish, shrimp, Corydoras, Otocinclus, Gouramis and Bettas. It's a fantastic foreground or even carpet plant that stays short but can also be grown as a floating plant or an epiphyte tied to driftwood or rocks. It can even be grown as a houseplant provided that the soil is kept very moist.
Hydrocotyle verticillata is a tough plant that is difficult to kill and likes colder water than most aquatic plants - making it a perfect plant for coldwater aquariums that house goldfish or native fish. It is only one of a few species that can be kept in Goldfish tanks without any problems.
Though it is a hardy plant, Hydrocotyle verticillata does relish good lighting which will encourage it to grow low to the ground, produce more leaves and spread horizontally along your substrate. Given high lighting, it will produce shorter internodes and denser foliage like a carpet plant. In lower lighting, H. verticillata will grow taller and produce leaves closer to the surface.
Unlike other Hydrocotyle species such as Brazilian pennywort (Hydrocotyle leucocephala) and Hydrocotyle tripartita, Hydrocotyle verticillata is not nearly as bushy and instead likes to grow in straight lines that branch along the bottom of your tank, occassionally sending up a leaf at each node. It is a fantastic plant for the foreground and the appearance of its vertical leaves at various spots in your aquascape looks beautiful and really adds interest to your aquarium.
In the past, this plant has been confused with the closely related Hydrocotyle vulgaris which is a larger plant native to various areas of the Eastern Hemisphere. Hydrocotyle verticillata, in contrast is a much smaller plant from the Western Hemisphere that is arguably better suited to aquariums.
While it prefers a soft, fine grained, loamy substrate, H. verticillata does not need to be rooted and can be grown floating or tied to hardscape, making it one of the most versatile plants you can get. It does not require CO2 but CO2 injection will dramatically increase the rate of growth. Otherwise, it really appreciates light and can even take periods of direct sunlight making it a perfect plant for a Walstad type "natural aquarium".
QUICK NOTES:
Type: Crawling horizontal stem plant
Position: Carpet, foreground, midground, floating or tied to hardscape. Can also be grown semi-emersed.
Difficulty: 2/5
Lighting: 3/5 – 5/5
CO2: Not required but increases the growth rate dramatically
Size: Leaves grow on petioles 3-10cm depending on lighting and conditions.
Growth Rate: Moderate to Fast depending on conditions
Water Chemistry: Prefers slightly acidic water - hardness unimportant
Temperature: 10C - 25C - does well in unusually cold water
Propagation: Separating the crawling "caulome" into sections with at least two nodes
Special requirements: Light, loamy substrate, good lighting
Emersed growth: Grows fast and beautiful emersed in terrariums or even pots with very wet soil. Will produce numerous caulomes that criss-cross the media surface and tolerates quite cold temperatures. Makes for a fantastic plant in a terrarium, vivarium or even just a glass jar on the windowsill in temperate climates.
