Synonyms: Acmella oppositifolia, Acmella oppositifolia var. repens, Spilanthes americana
Light Needs: Medium
Plant Structure: Stem
Region: North America, South America
Location: Southern USA to Paraguay
Size: Stem width 2 inches
Growth Rate: Moderate
Can Be Grown Emersed: Yes
Distributed from the southern United States to South America, Acmella repens has been known by several names, among them Spilanthes americana and Acmella oppositifolia var. repens. This fairly common resident of wet ditches and other wet areas is one of the relatively few representatives of the very large family Asteraceae to be used in aquaria.
While capable of growing without carbon dioxide supplementation, optimal and attractive growth more or less requires it. When grown in good conditions, the rigidly upright growth pattern and moderate growth speed of A. repens lend it easily to the kind of tiered stands seen in Dutch style aquascapes. Under strong illumination, a reddish stem and purple flush on leaves appear; otherwise, all growth is green. Emersed propagation is unproblematic and much faster than with submersed plants. Grown as a marginal plant around ponds, attractive yellow inflorescences appear in late summer. No particular nutrient sensitivities are known, but A. repens is unfortunately vulnerable to some snails.
Not sold commercially, Acmella repens can be acquired from other hobbyists or from suitable habitat in its native range
Photo #1: Submersed US and International Copyright 2011 by Tim Gross All Rights Reserved
Photo #2: Inflorescence US and International Copyright 2010 by Kris Weinhold All Rights Reserved
Photo #3: Inflorescence US and International Copyright 2010 by Kris Weinhold All Rights Reserved