Begonia aequilateralis is a species of begonia known only from the Sungai Buloh area of Selangor in Peninsular Malaysia.
"...probably the most endangered begonia in the Peninsula, being known from a single small population in a forest area currently being cleared." - Kiew, p. 261
The species was first described by Edgar Irmscher in 1929.
References
, Mitteilungen aus dem Institut für allgemeine Botanik in Hamburg 8:134. 1929 , Begonias of Peninsular Malaysia :261-264, 2005
tfbc.frim.gov: "Saving a highly endangered begonia"