L. punctata is distinguished by its reduced frond prophyllum, root tracheids, external anther locules, and also by well-supported molecular evidence provided by allozymes and cpDNA sequences. (Les & Crawford, 1999). \"All of the roots penetrate the prophyllum (a scale surrounding the base of the frond that covers the point of attachment of the roots).\" (Jacono, 2002). “Many duckweeds, including our native Spirodela polyrrhiza, survive climate in cold regions by forming an abundant supply of turions (rootless fronds rich in starch) that sink to the warm bottom to overwinter. The inability of Landoltia punctata to form turions accounts for its absence in the northern and Midwestern United States. Its fronds are sensitive to severe frosts and plants are reportedly limited by absolute minimum temperatures <- 20 C (- 4 F). Under long-day photoperiods Landoltia punctata may sometimes form resting fronds. These are small, delicate single fronds with only one fragmentary root. High in starch, they function comparably to turions in that they are more capable than normal fronds in surviving unfavourable conditions such as storms and light frost. However, they do not sink to the bottom and thereby do not provide overwintering protection in zones with severe winters.” (Jacono, 2002). L. punctata can survive drought by seed in arid regions such as Australia, which has led experts to believe that it has the potential to become established in arid southwestern US states. (Jacono, 2002).
Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Expert review underway: Tyler J. Koschnick, PhD \ \ Aquatics Research Manager \ \ SePRO Corporation USA
Publication date: 2006-11-08
Recommended citation: Global Invasive Species Database (2017) Species profile: Landoltia punctata. Downloaded from http://www.iucngisd.org/gisd/speciesname/Landoltia+punctata on 16-12-2017.