196 TilE FLORA OF SINGAT JRE 
S. sp. Small plant, Bukit Timah, No. 6547, 
Psilotum flaccidum Wall. On trees in mangrove swamps, Kranji 
P complanatum Sw. Mangroves, Sungei Morai, Kranji. 
RAIZOCARPEAE, 
Azolla pinnata R. Br. A small floating plant, Ditches, common, 
Tanglin, Ang Mo Kio, Galang. 
Addenda. 
Ludwijyit parviflora Rox). Ditches, Tanglin, 
Enhydrias angustipetala Ridl. Common in ponds ani ditches, 
Tanglin, This new genus must be put in place of //ydrilla 
verticillata, for which it was mistaken, 
