Although some species of the genus Geranium are cultivated, the “geraniums” of the florist, including those commonly grown as house plants, are various species and hybrids in the genus Pelargonium, plants native mostly to South Africa.
The complex fruit in this family is a schizocarp, consisting of five 1-seeded mericarps (which may split open) at the base of an elongate beak which terminates in the more slender style. (Measurements of this stylar tip do not include the 5-fid apex.) At maturity, the mericarps separate, each with an “awn” that peels away upwardly from the beak and often remains attached to the apex of the beak. The awns are hygroscopic and curve outward or spiral with changes in humidity.
1. Leaves pinnately lobed or dissected; awn of mericarp ± spirally twisted at full maturity.
1. Leaves palmately lobed or compound; awn of mericarp curving in a simple arc or coil at maturity.
All species found in Geraniaceae
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 11, 2017. http://www.michiganflora.net/family.aspx?id=Geraniaceae.