Pelargonium tetragonium and friends

Pelargonium tetragonium 
square stemmed Pelargonium

This geranium is one which always draws comment when in flower as the soft pink flowers with their 'winking' centre stand up and demand to be noticed amongst a twiggy mass of pencil thin stems and few leaves. It is usually grouped with succulent plants and has similar requirements. Growing to about 45cm it can sprawl about and will benefit from regular pruning to make it more compact and manageable.Of similar nature is Pelargonium gibbosum the "Gouty Geranium",which is noted for its highly perfumed (at dusk) chartreuse coloured flowers and strangely knotted and swollen stems.The dusty coloured grey green leaves and sprawling untidy habit really make this one for the collector. Having grown it, I passed it on to someone else as it always looked as if the cat had gone to sleep on it .

While the above two species are South African in origin ,it is worth noting a couple of Australian species which are excellent garden plants. Pelargonium rodyneyanum Magenta Cranesbill is a small clump forming species no larger than 30 cm high. It has a deep thickened tap root and in my experience it seems to die down to this central tap root usually in dry weather and regrow under more favourable conditions. The other species of note and more common is Pelargonium australe which is a lovely rounded plant about 50cm in diameter and found from the coast to the alps. Unfortunately it is not appreciated enough to be included in home gardens. A local form growing on the high coastal sand dunes at East Corrimal beach has pale pink flowers and neat habit.

The colours magenta and chartreuse mentioned above are shown below.
The colour Magenta is named after a city of Italy ,near which the Austrians were defeated by the French and Sardinians in 1859.

Chartreuse is a greenish yellow coloured Liqueur.

2017 update: I have these Pelargoniums for sale though usually in limited numbers. I put a batch of P tetragonium thorough the plant trade market last year and they all sold.