PELARGONIUM

Pelargonium is a wide genus, and it occurs in diverse growth habits: from herbaceous annuals, to shrubs, to succulents to caudiciform plants. Caudiciform plants are plants equipped with a caudex, which is an enlarged, wooden subterranean stems with the function to store water and nutrients to overcome the dry season.

KEY FEATURES

Pelargonium is a wide genus of around 280 species in the family Geraniaceae. These plants are widespread in both temperate and tropical areas of the planet, being actually native to Africa, with a high number of species coming from South Africa.

Pelargonium is popular also for its uses in aromatherapy. It has in fact many properties: rebalancing properties of the nervous system, antidepressant, anti-inflammatory, soothing, astringent and antiseptic. Its functions also include stimulating the lymphatic system, toning the liver and kidneys. Among its main uses there are also the treatment of acne, burns, blisters, eczema, arthritis, neuralgia, sore throat. Some species, instead, have become extremely popular as garden plants and houseplants, appreciated either for their pleasant scent, and because it’s not so tough to grow them.

Pelargonium are often confused with Geraniums however, while Geraniums are usually herbaceous annual plants which die down in Winter and are mainly native to temperate regions, Pelargoniums are perennial plants, evergreen or deciduous depending on the specieus, often (especially the species from semi-arid areas) equipped with a caudex or with an enlarged rootstock.

Pelargonium is a wide genus, and it occurs in diverse growth habits: from herbaceous annuals, to shrubs, to succulents to caudiciform plants. Caudiciform plants are plants equipped with a caudex, which is an enlarged, wooden subterranean stems with the function to store water and nutrients to overcome the dry season. Caudiciform plants are in fact particularly widespred in semi-arid areas, with low rainfall levels, and a clear separation between a humid and a dry season.

The stem can be herbaceous or wooden, succulent or not, depending on the species. Also leaves are different according to the species, however, usually, the most frequent shapes are peltate (peltate is a botanical term which refers to the position of the petiole junction which, in peltate leaves, lies in the center of the leaves), and laciniated, which are profoundely etched and irregular kinds of leaves.
In some species, leaves are covered in a dense, whitish hair. Some species are particularly scented, such as P. odoratissimum.

In caudiciform species, the caudex often take on irregular, lumpy shapes (such as in P. alternans), or either a globose, more or less oval one (such as in P. carnosum).

Flowers are what have made these species so popular among ornamental gardeners. They are also the main feature that distingueshes Geraniums from Pelargoniums: they have a single symmetry plan, unlike Geraniums flowers which show a radial symmetry.

However they are different according to the species, a common feature is that they are always five-petaled and grouped in umbrella-shaped inflorescences. The lower three petals are different, usually bigger, than the upper two ones. The colours of the petal vary according to the species.

Fruits have the typical shape of a stork’s beak and are the main reason for the name of the genus.