Sharp, metallic geranium leaf. 
Probably the most prototypical of all the geranium synthetics
Geranium Pyran/Pelargene  is very powerful: even a 1% solution is great for adding sprigs of greenery or indeed an very convincing greenhouse effect. 
Beyond its use in the potting shed, Pelargene is also useful for reducing reliance on Rose Oxide, which some perfumers are now doing, for example with Dihydro Rose Oxide