There were 2 accepted species found [distribution filter:
1 Phylohydrax carnosa (Hochst.) Puff distributionfilter: global
homotypic synonyms:
Diodia carnosa Hochst.; Hydrophylax carnosa (Hochst.) Sonder;
links:    
IPNI (International Plant Names Index)   
WFO (World Flora Online)   
Google   
Flickr
2 Phylohydrax madagascariensis (Willd. ex Roemer & Schultes) Puff distributionfilter: global
homotypic synonyms:
Hydrophylax madagascariensis Willd. ex Roemer & Schultes; heterotypic synonyms:
Hydrophylax madagascariensis Willd.;
links:    
IPNI (International Plant Names Index)   
WFO (World Flora Online)   
Google   
Flickr