Smithonian MuseumSix design concepts for the future national black history museum planned for the National Mall were unveiled Friday, mostly breaking with the tradition of boxy Smithsonian Institution museums by showcasing earthy elements and varied shapes.

Any one of the proposed designs for the National Museum of African American History and Culture could mark a sharp departure in the architecture between the Capitol and Washington Monument for what could be the final museum added to the area.

“The mall is a place of evolution,” said museum director Lonnie Bunch, who will lead a jury in selecting a final design team by April 14 to recommend to the Smithsonian secretary and governing board. “In some ways, this is pushing the mall to the next stage of evolution.”

The proposed designs will be on public view through April 6 in the Smithsonian Castle, where visitors can submit comment cards that will be reviewed once a design team is chosen, Bunch said. The building is slated to open in 2015 as the first certified environmentally friendly museum on the mall, with groundbreaking in 2012.

The designs are all quite different in their outside appearance but share the museum’s vision for exhibits, including an iconic slave ship marking a journey from Africa and stories from the slavery experience, galleries devoted to music, sports and culture, and space devoted to the Civil Rights movement and beyond.

Bunch has called for a building that evokes “the resiliency, optimism, spirituality and joy” of the black community. On Friday, Bunch said the recent death of historian John Hope Franklin reminded him that “this museum must help the nation see all the dark corners of its history.”

Perhaps the most daring concept in the design competition came from the team Moody Nolan Inc., in association with Antoine Predock Architect PC. It features natural materials rising from the ground — stone, moss and grasses — with wetlands that extend inside the museum. African woods, harvested from fallen trees and other sustainable means would adorn the interior.

The shape is abstract and its materials based in part on research about the mall’s geography. A glass roof at the structure’s center depicts a pattern from tribal Africa, said Don Stastny, a competition adviser for the Smithsonian who will not vote on the design.

The design team Diller Scofidio + Renfro, in association with KlingStubbins, submitted what appeared to be a hovering limestone structure wrapped in a glass veil. A huge picture window in the structure would overlook the Lincoln Memorial.

The building “emerges from the ground as if its seeds were always planted but not yet germinated,” the architectural team wrote.

Another proposal calls for a glowing, layered structure that changes in appearance with the angle of the sun. The concept by Freelon Adjaye Bond, in association with SmithGroup, involves a bronze crown topping the museum.

The team led by acclaimed architect Sir Norman Foster of London presented an oval-shaped structure that winds the visitor down a ramp, through a garden and into the darkness of slavery, then upward through four stories to the light at the top of the building. It includes environmental features, such as irradiated heat and cooling and proposes to draw at least 9 percent of its energy from renewable sources.

Another architectural luminary, I.M. Pei, worked with the team Devrouax + Purnell Architects to create a design calling for a boxlike structure with pieces carved out to reveal curved walls inside. It would be unique but still more like other buildings on the mall than the other proposals.

Finally, a proposal from Moshe Safdie and Associates, involves a smaller footprint above ground and more than a third of the museum space hidden below street level. It would be engineered to bring in natural light with woven wood slats and skylights to the basement levels.

Any of the designs could be integrated with the Washington landscape, said Stastny, the Smithsonian’s design consultant.

“This is a building for hundreds and hundreds of years,” Stastny said. “It probably will become the next landmark of Washington.”

Copyright 2009 The Associated Press.