Richardia grandiflora has been on the radar screen for the invasive plant list since 1999. The common name is large-flower Mexican clover (a misnomer – it originated from South America). Initially considered a species found just in disturbed edges, an increasing volume of occurrence records in natural areas raised concerns and promoted it to the rank of a Category II invasive plant in 2013. There currently are vouchered specimens from 21 Florida counties, from Volusia and Hillsborough counties, southward (http://florida.plantatlas.usf.edu/).
The full extent of its range is uncertain because it also has been seen in the coastal strand community of a national seashore in the western panhandle (Escambia County). This member of the coffee family (Rubiaceae) has invaded scrub, pine rocklands, prairie, coastal strand and beach dune plant communities. Label data from vouchered specimens describe scattered plants to dense patches that grow with or crowd out native endemic plants such as Selaginella arenicola, Asclepias curtisii, Lechea spp., Conradina grandiflora and others. This sprawling herb with a deep central tap root returns readily after fire and becomes established where there is open, bare ground. It moves into natural areas from edges, trails and fire breaks by natural means of dispersal. Mowers and other equipment appear to be dispersal vectors, causing lawns and natural areas to form low mounds of flower "snow."
From New Species for the Florida Exotic Pest Plant Council’s 2013 List of Invasive Plant Species, Wildland Weeds, Spring 2014, Supplement 1—Online Only—www.fleppc.org