Stack, chimneylike, and threadlike assemblies have previously been proposed for the structure of disodium cromoglycate (DSCG) aggregates in aqueous solutions. The results of the synchrotron x-ray scattering investigations reported here reveal the formation of simple columnar assemblies with π-π stacking at a separation of 3.4 Å between the DSCG molecules. Lateral separation between the assemblies is concentration and temperature dependent, varying from ∼35 to 42 Å in the orientationally ordered nematic (N) phase and from 27 to 32 Å in the columnar or middle (M) phase having long range lateral positional order. The assemblies' length depends on concentration and consists of ∼23 molecules in the N phase, becoming three to ten times larger in the M phase. The scission energy is concentration dependent in the N phase with values ∼7.19 ± 0.14 k_{B}T (15 wt %), 2.73 ± 0.4 k_{B}T (20 wt %), and 3.05 ± 0.2 k_{B}T (25 wt %). Solutions of all concentrations undergo a spinodal decomposition at temperatures above ∼40 °C, resulting in DSCG-rich regions with the M phase and water-rich regions in the N and isotropic phases.