Carolyn Moss is known to TreeHuggers as a harsh taskmaster when it comes to installing green roofs. At the Interior Design Show her firm, Moss Sund, collaborates with Fig Forty to produce a rainwater harvesting storage system that can hold 100 gallons and acts as a green wall, or perhaps more accurately, a green pillar.
"CISTA is a rain water harvesting system designed for urban environments. It provides storage for rain water within a vertical planted frame, allowing us to conserve water and increase green space." More at MocoLoco
Moss Sund in TreeHugger:
Green Roofs: A primer
Raising the (Green) Roof!!