US online giant Amazon has unveiled plans for a futuristic greenhouse style headquarters "where employees can work and socialize in a more natural, park-like setting."

The Internet company revealed photos and sketches this week of the plan to be submitted to Seattle city officials, becoming the latest of the technology heavyweights to unveil a bold new headquarters plan.

"The generative idea is that a plant-rich environment has many positive qualities that are not often found in a typical office setting," according to Amazon's proposal.

The company revamped its original plan from a six-story rectilinear structure to "a series of intersecting spheres with ample space for a wide range of planting material," the document said.

"While the form of the building will be visually reminiscent of a greenhouse or conservatory, plant material will be selected for its ability to co-exist in a microclimate that also suits people."

The plan includes 65,000 square feet (6,000 square meters) of office space and high bay spaces on five floors capable of accommodating mature trees.

The exterior will be multiple layers of glass supported by a metal framework. It will have dining, meeting and lounge spaces, as well as a variety of "botanical zones modeled on montane ecologies found around the globe," Amazon said.

Google, Facebook and Apple also have new headquarters planned in their respective locations in Silicon Valley, California.