Diascia whiteheadii flower from above

Seen from above, the outside of the Diascia whiteheadii corolla shows dark purple lines on the spur bases, fading in the upper parts. The shape of the corolla, crowned by curving spurs, might have been inspirational to milliners producing hats for Viking women, if only those avid explorers had ever ventured as far as southern Africa to discover this beauty.

The dark purple area around the spur bases has a row of yellow spots or windows, petering out into gold dust speckles. These spots match those found inside the corolla; maybe a kind of nectar guide, here an oil guide. Whats the use of a window that shows itself on only one side of a wall?

A pointed, green sepal tip is visible between the spur bases over the slender flower pedicel (Manning, 2007; Manning and Goldblatt, 1997; iNaturalist).