The flowers of Memecylon umbellatum are in clusters of distinctly peduncled dense umbels. The inflorescences are about 1.5-3 cm across and they are axillary or on lateral tubercles with short peduncles.
The cup-shaped calyx is 3 mm wide, white-pinkish coloured and slightly 4-lobed.
The corolla is composed of 4 orbicular, deep blue and 3 mm wide petals.
There are 8 stamens with blue, filiform, 4 mm long filaments and with blue and 1 mm long anthers. The style is purple-blue coloured and 6-7 mm long.
The flowers of Memecylon umbellatum are fragrant.