Pelargonium tetragonum flowers

The flower of Pelargonium tetragonum has features typical of several other local species in its broader genus, as can be seen from some pictures in this Album. The bigger upper petals have fine dark lines in their lower, narrow sections. These lines disappear into the light colour of the broader, sometimes lobed upper petal parts. The lower petals, usually two and not three of them, as commonly found in many other Pelargonium species, share the creamy white or pale pink base colour of the upper two, but without the line markings. They do, however, have outwardly curving tongue-like tips, similar to the recurving present in the upper petals. The maroon coloured stamens protrude markedly in a bunch that curves upward about halfway along its length. There are narrow and short, sharply pointed, green sepals pointing outwards from the flower base.

Descriptions of this flower by Vlok and Schutte-Vlok (2010) and other sources mention the existence of two lower petals only. There are, however, photos on the Internet with similar looking flowers under the same name that have three lower petals. The question arises as to whether those may be the result of some hybridisation?