Common Name: Pelargoniums
Description: Annual or perennial herbs or low shrubs.
Leaves opposite or alternate, usually simple or dissected and almost compound, margins toothed or lobed, hairy with long non-glandular and short glandular hairs or ± glabrous, often aromatic; leaves becoming smaller up stems.
Inflorescences cymose umbels. Flowers zygomorphic. Sepals 5, fused towards the base and the posterior one prolonged downwards into a spur fused to the pedicel. Petals 5, clawed, free, longer than sepals, white to deep pink, posterior ones usually larger and often marked with darker spots and lines. Stamens 10, usually ± fused towards base, 3–8 fertile.
Mericarps separating from the column and without a pronounced tuft of hairs, eventually releasing the seed; awn curved and with ± long hairs on the inner surface.
Distribution and occurrence: World: c. 250 species, temperate regions, especially southern Africa. Australia: c. 11 species (6 species endemic, 4 species naturalized), all States.
Many species are cultivated as ornamentals, and these are commonly referred to as 'Geraniums'. P. X hortorum L. Bailey, the Zonal Pelargonium, is a widely cultivated hybrid and sometimes persists around habitations, but it is not considered to be naturalized. It is distinguished by the velvety leaves that usually have a dark ring around the middle. Note: in the illustrations the arrow indicates the base of the sepal spur on the pedicel.
Text by G. J. Harden
Taxon concept:
Taxa not yet included in identification key
Pelargonium sp. Striatellum (G.W.Carr 10345)
| | Key to the species | |
| 1 | Leaves deeply dissected, pinnatisect or palmatisect; plants hirsute, hairs harsh | Pelargonium asperum |
| Leaves shallowly lobed or more or less entire; plants villous to minutely pubescent, hairs soft | 2 |
| 2 | Leaves with acute lobes | Pelargonium x domesticum |
| Leaves with obtuse lobes or almost unlobed
Back to 1 | 3 |
| 3 | Fertile stamens 3–5 or rarely 6; perennial stems short and not succulent | 4 |
| Fertile stamens 6–8 or rarely 5 and then the perennial stems more or less succulent
Back to 2 | 5 |
| 4 | Calyx densely hairy; sepals obtuse | Pelargonium helmsii |
| Calyx with scattered hairs; sepals acute
Back to 3 | Pelargonium inodorum |
| 5 | Spur usually shorter than the calyx lobes; calyx villous, hairs non-glandular and long | 6 |
| Spur at least as long as the calyx lobes; calyx glabrous or pubescent and hairs mostly glandular and short, sometimes mixed with some longer non-glandular ones
Back to 3 | 7 |
| 6 | Bracts broad-ovate, c. 6 mm long and 2.5 mm wide; plants shrubby; naturalized in coastal sites in the Newcastle and Sydney districts | Pelargonium capitatum |
| Bracts lanceolate, c. 3 mm long and 0.5 mm wide; plants herbaceous; widespread on the coast and inland districts
Back to 5 | Pelargonium australe |
| 7 | Leaves more or less glabrous on both surfaces; flowers deep pink | Pelargonium rodneyanum |
| Leaves densely hairy on both surfaces; flowers predominantly white
Back to 5 | Pelargonium fragrans |
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