Geranium viscossisimum / sticky geranium

Adjectives: exposed, forest openings, geranium-like leaves, highly visible, interesting bits, native, sticky, widespread

Also known as: purple sticky geranium

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This is a very common and perennial plant throughout The Valley and up the mountain sides, mostly in shaded, moister areas. The flowers come in a variety of shades from white, through pink, to red, and frequently have darker lines pointed toward the center… possibly as “bee guides” to show the insects where the nectar is. The flowers are bee and butterfly pollinated. The fruit is long and pointy, and seeds disperse by explosive, “ballistic dispersal”. This makes seed collection difficult unless the plants are covered with nets or bags to catch the seeds.

One of the more distinguishing features of this plant is the deeply cut lobes of the leaves and the prominent veins. Other plants have a similar feature, but for me, these all have geranium-like leaves. After the flowers fade, the fruit is a pointed thing about an inch or so long, and after it explodes, the different lobes remain tightly curled where the seeds used to be. See photos of that in the gallery.

Interesting bits – Other than the biology, I love the Latin specific name… “most viscous”. It is by no means the only sticky plant in the area, but the stem at the base of the flower are covered with sticky hairs (glandular trichomes). The stickiness itself is the result of resins and phenolic compounds exuded by these structures. These are a bit hard to see without a hand lens (magnifying glass). As some glandular trichomes are used by carnivorous plants to trap and digest small prey, it has been proposed, and sort of tested, that this plant’s sticky hairs can make it at least “protocarnivorous”. At present, I consider this a “cute” idea at best given that the plant doesn’t seem to be found in low nutrient or anoxic environments. Still, it would make for a good halloween movie.

Finally, from A. A. Milne’s “The Dormouse and the Doctor”
     There once was a dormouse who lived in a bed
     Of delphiniums (blue), and geraniums (red)…