The flower of Pelargonium curviandrum becomes 25 mm in diameter. Five narrowly lance-shaped sepals with acutely pointed tips form the calyx where nectar, the pollinators’ reward, is found. The sepals have purple-brown central keels or ribs visible on both surfaces and a few long hairs at their tips.
The pale cream to nearly white corolla has a characteristic pair of long, narrow upper petals, oblong with bulges at the tips. They are erect and close together, marked in dark maroon or purple. The three unmarked lower petals are narrowly club-shaped with rounded tips, angled widely apart and borne about horizontally.
The four fertile stamens grow in two pairs of unequal length, the filaments white and curving up in their upper halves. They bear orange anthers that drop off when the stigma ripens. The long style is white and thin like the filaments, ending in five tiny stigma branches. Pollination is done by long-tongued flies (Vlok and Schutte-Vlok, 2010; www.llifle.com).