dl-Threoninium oxalate

In the title compound, C₄H₁₀NO₃⁺˙C₂HO₄⁻, the dl-threonine mol­ecule exists as a cation and the oxalic acid mol­ecule in the mono-ionized state. The mol­ecules aggregate into infinite parallel layers which extend along the diagonal of the ac plane. These layers have no hydrogen-bonded interactions between them, only van der Waals interactions. The semi-oxalate ion deviates far from planarity. No classic head-to-tail hydrogen bonds are observed.