Know your fynbos: The private life of pelargoniums

Know your fynbos: The private life of pelargoniums

Perhaps the most brilliant feature of pelargoniums is their aromatic scent. Sweet rose, citrus and peppermint are just some of the fragrances you’re likely to get a whiff of while walking through the fynbos with any of these bright, evergreen shrubs are around.

Commonly known as geraniums, pelargoniums are most easily spotted in spring and summer, when their gorgeous pink, white, purple and occasionally red-orange, flowers come into bloom. They form part of the family Geraniaceae, and comprise about 280 species across the world, with 245 of these native to southern Africa – mostly in the Western Cape.¹

 

What to look out for:

• Leaves: The leaves of the pelargoniums you are likely to see on the Cape Peninsula vary in size, but are most often bold-textured and thick, sometimes with tiny hairs that make them look velvety. They are usually heart-shaped or palmate, with three to five ‘lobes’ that are cupped at the base to allow the pooling of water on the leaf blade.² Stems are thick and upright with the leaves arranged alternately, and leaf veins are often dark and prominent.³ When bruised, the foliage gives off a scented odour, depending on the species.³

 

• Flowers: Pelargonium flowers are usually clustered together on thick upright stems, making them dramatic and showy when in full bloom. You’ll know it’s a pelargonium because each flower has five petals, with the upper three petals differing from the lower three petals in that they are usually wider with more distinctive dark markings. This makes the flower bilaterally symmetrical, or zygomorphic, meaning that it has only one plane of symmetry.⁴

 

You might not know: 

• Stork’s bill: The name pelargonium is derived from the Greek word pelargos, meaning ‘stork’, as its fruit is said to resemble the beak of a stork.³ In the United States, pelargoniums are widely known as ‘storksbills’.⁴

 

• Geranium or pelargonium? While geranium is the common name often given to pelargoniums, it is also the botanical name of an entirely separate plant genus commonly known as the cranesbills. Both storksbills (pelargoniums) and cranesbills (true geraniums) fall under the family Geraniaceae, but the key difference between them can be found in their flowers: while pelargoniums have three lower petals that differ from the upper two (making them zygomorphic), geranium petals are all the same (making them actinomorphic, which means they have radial symmetry).⁴

 

• Perfumes, pest-repellents, culinary delights: Some of the pelargonium species you’re likely to see (or smell!) around the Western Cape include the rose-scented pelargonium (Pelargonium graveolens), used in the production of geranium oil for the perfume trade,⁵ the lemon-scented pelargonium (Pelargonium citronellum), often used as a natural insecticide with its pungent lemony fragrance,⁵ and the peppermint-scented pelargonium (Pelargonium tomentosum) which can be used as a culinary herb for adding delicious flavours to baked goods like chocolate cakes.⁶

 

References:

1. Pelargonium [Internet]. Biodiversityexplorer.org. 2017 [cited 31 July 2017]. Available from: http://www.biodiversityexplorer.org/plants/geraniaceae/pelargonium/index.htm
2. Pelargonium x hortorum [Internet]. Hvp.osu.edu. 2017 [cited 31 July 2017]. Available from: http://hvp.osu.edu/pocketgardener/source/description/pe_torum.html
3. Pelargonium citronellum | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 31 July 2017]. Available from: http://pza.sanbi.org/pelargonium-citronellum
4. Pelargonium [Internet]. En.wikipedia.org. 2017 [cited 31 July 2017]. Available from: https://en.wikipedia.org/wiki/Pelargonium
5. Pelargonium graveolens | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 31 July 2017]. Available from: http://pza.sanbi.org/pelargonium-graveolens
6. Pelargonium tomentosum | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 31 July 2017]. Available from: http://pza.sanbi.org/pelargonium-tomentosum