The flowers of Pelargonium trifidum are creamy white here, their petals slender. The upper petal pair is marked at the base in dark maroon to red-purple blotches from which tiny lines protrude a little distance up the petal surfaces. The lower three petals are unmarked. The petal shape is oblong, the upper ones wider and sometimes widening in the centre into an elliptic form. Petal tips are square, rounded or notched.
The flower dimensions are 3 cm in diameter, the hypanthium, floral cup or tube about 6 cm long.
Flowering happens in spring and summer (Vlok and Schutte-Vlok, 2015; iNaturalist).