Cycas siamensis is a species of Cycad endemic to Myanmar, Thailand, and Vietnam.
Cycas baguanheensis L.K.Fu & S.Z.Cheng
Cycas intermedia B.S.Williams
Cycas siamensis subsp. siamensis
Epicycas siamensis (Miq.) de Laub.
Bot. Zeitung (Berlin) 21: 334 1863.