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PELARGONIUM PROFILE – PELARGONIUM OBLONGATUM

By Dr. Wayne Handlos

                   

Pelargonium oblongatum  lowers Stem, leaves & persistent leaf bases                           Typical P. oblongatum from

                                                                                                                                 illustration in Van der Walt 1977

Some years ago I bought several Pelargonium plants from Dr. Robin Parer including one labeled

P. oblongatum. The plant has thrived for me – proving its toughness. I have enjoyed the once yearly

display of flowers which are larger and more showy than those of many of the true species.

A large number of pinkish flowers are produced each spring by this plant which is summer

dormant.

Only this year did I become aware that the flower color of my plant was not typical for this

species. The usual flower color is pale yellow with red/purple lines on the two, large, upper

petals. On my plant the flowers are distinctly a light pink with reddish purple veins in the two

upper petals. Each flower has a long nectar tube which presumably contains a sweet reward for

a pollinator – probably a “long-nosed fly”.

As far as I can tell, all the other characteristics of this plant are the same as the typical P. oblongatum.

The tuber is elongate, smooth, partially above ground, with perisitent, dried leaves and leaf

bases.

Am I excited that I’ve got something new and different? No, not really. But here is something

that merits some further study.

Is this just a naturally occurring color variant? Such variants are widespread in many species of

flowering plants including various species of Pelargonium. Such variants have been sought by

plant collectors over the centuries and account for many of our garden cultivars.

Or is this some kind of hybrid with the pink color introduced from another parent? Hybrids

occur occasionally in nature including some between various species of Pelargonium. Many (if

not most) of the new introductions by the large commercial horticulture/floriculture companies

are newly synthesized hybrids – selected for desirable characteristics.

Or is this a chance mutation or “sport”? A mutation or sport is a change in the genetic makeup

of the plant which modifies it usual characteristics. Such changes are known as the source

of many Pelargonium cultivars.

I don’t know the answer to the questions I have just posed but with study we could probably

determine the correct answer. What a wonderful project for a dedicated high school or college

student!

© 2010, Central Coast Geranium Society (CCGS )