Lamduan (ลำดวน) refers to a flowering plant belonging to the Annonaceae family. It is native to Southeast Asia and is recognized by various names in the region, including rumduol in Khmer.
The plant is commonly cultivated as an ornamental species. It holds significant cultural status as the national flower of Cambodia and serves as the provincial flower for Sisaket province in Thailand. In some botanical contexts, it is considered to be the same species as Sphaerocoryne affinis.