The hardiest species of Pelargonium, standing all but the worst winters outside in much of the UK as long as a position which avoids too much rain can be provided. A predominately South African genus of around 280 species, P. endlicherianum comes from Turkey and Syria ( in the cooler parts of the desert). A good alpine house species where excessive winter wet can easily be avoided (shown here in the alpine house at RHS Harlow Carr)
P. endlicherianum is a clump-forming perennial with thickend rhizomes which run just below or across the surface of the soil. In its normal form it can be over 40cm in height. The flowers are relatively large and comprise two large, upper, carmine-magenta petals and three much smaller lower ones, around 2.5cm in total length. The umbel arrangement can contain upto fifteen individual flowers.
I grow a form from Gothenburg Botanic Garden seed under the collection number KKPS 9316, from Artvin which is particularly dwarf; the orbicular to kidney shaped leaves being only around 1cm in diameter whilst retaining the relatively large flowers. Any ordinary well drained soil will surfice, with plenty of sunshine to ripen the rhizome. Propagation is easy from seed, stem-cutting or division of the rhizome.