Sunday, September 23, 2012

Railroad vine

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Railroad vine
Ipomoea pes-caprae

I discovered this railroad vine growing along the side of the road, but I most often see it growing on beach dunes.  As you might guess – railroad vine is heat, salt, and drought tolerant.  An early pioneer plant, the vine sends out thick, flexible runners with roots at each node that stabilize shifting dune sands.  The runner I sketched was easily the diameter of my little finger. These runners are the source of the common name of railroad vine; the “railroad tracks” can cover quite a distance as shown in this video. 

Railroad vine is a member of the morning glory family (Convolvulaceae), which includes a culinary favorite, the sweet potato.  The vine bears the typical trumpet-shaped bloom of morning glory, in shades of lavender, violet, magenta, and pink.  In the bright sunlight, the colors seem to glow.  The blooms are held erect on a prostrate vine, and are a food source for bees and butterflies. 

The blooms are more vivid than my tools can show!
The flowers open in the morning, fading in the heat of the day.  The fertilized blooms produce seed pods containing four brown seeds.  Although the seeds are poisonous, they’ve been used historically for medicinal purposes.

The leathery leaves grow up to 4 inches long, the two-lobed kidney-shape suggesting a split goat’s hoof (Latin pes-caprae, foot of the goat).  Long petioles (leaf stems) support the upright leaves, often folded along the midrib. 

The sap is used as a natural first aid treatment for jellyfish and insect stings, and the family in general has many beneficial properties. 

The Sketchbook Project sketchbook,
Pitt Artist pen in black, size XS for the sketch, and S for the text
Kimberly watercolor pencils, Derwent Inktense,
Niji Aquabrush, medium size.

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