Three's a Pair! - Part 2
Melodic Minor Triad Pairs - "Rhythm Changes" Bridge
As mentioned in that article, the pair of adjacent triads which most captures the sound of Melodic Minor are the Major & augmented triads, built off of the 4th and 5th scale steps, respectively.
(In C Melodic Minor = F Maj.(F-A-C) & G aug. (G-B-Eb) triad pair).
However, the quality of the pure diatonic triad built on 5th step of Melodic Minor is not augmented, but Major - G Maj. = G-B-D, which is exactly the same in C Major.