What is the second fastest growing land plant on earth?

Question

Not aquatic plants like kelp. Bamboo is the fastest, what is next?

Answer 1

Bamboo:
Bamboo can outgrow any other plant in the world. It is as if its entire lifespan is one enormous growth spurt. To see for himself how fast bamboo can grow, Janssen once marked a stalk while visiting a bamboo plantation. He remembers taking a walk around the plantation and returning again to the marked stalk. "In two hours, it had grown above the mark by a few centimeters," he says. A Japanese scientist once measured what is believed to be the fastest growth rate for any bamboo. A culm of ma-dake, Japan's most common bamboo, grew nearly four feet in one 24-hour day.
http://www.pbs.org/wgbh/nova/lostempires/china/miracle2.html

Filamentous hyphae:
It has also been estimated that if all the filamentous hyphae produced in one day by a single massive soil fungus permeating acres of forest soil were laid end to end, they could extend for nearly a mile--but this is not substantiated.
http://waynesword.palomar.edu/ww0601c.htm#growing

Algae:
Dr. Isaac Berzin is the founder of GreenFuel Technologies Corporation. Berzin is working on a prototype that uses algae to convert power plant emissions into biofuels. Dr Berzin insists that algae are the fastest growing plants on earth. Their doubling time is measured in hours.

He grows algae because they're super rich in oil. In some species, oil accounts for half the little creature's body mass. In fact, algae synthesize 30 times more vegetable oil per acre than plants like sunflowers or rapeseed.

Algae biodiesel can be used to run engines, or converted into methane or fermented into alcohol. And here's the best part: algae eat carbon dioxide for breakfast, lunch and dinner. And one thing the global warming world has too much of is CO2 from fossil fuel burning power plants.
http://www.loe.org/shows/segments.htm?programID=06-P13-00002&segmentID=3