Field of Science

Friday Fabulous Flower - Geranium?


This time of year often requires a visit to the glasshouse to find something nice in flower, and this lovely "geranium" reminded TPP of another common name/scientific name source of common confusion.  In your local garden shop this plant was without doubt sold as a Geranium, and TPP has a number of Geranium species in his garden, but all of them have radially symmetrical flowers where five lines can be drawn that will divide the flower into identical halves.  Clearly this flower has a single line of symmetry, so it is bilaterally symmetrical, or zygomorphic.  This works well for lining up with potential pollinators which are also bilateral, and the floral markings serve as a guide probably absorbing in the infrared wavelengths.  The five lobed stigma is radially symmetrical. Well, this "geranium" is actually the genus Pelargonium (probably a hybrid, P. x hortorum). These make nice potted plants because they are fairly drought tolerant, many having a Mediterranean origin. Most gardeners though do call these plants a geranium, which is also a genus, and both genera are in the same family so naturally they have quite a few similarities. Pelargonium cultivars are not winter hardy and there are no native species in N. America.

No comments: