Drymonia coriaceae (USBRG 1999-212)
Photo by Leslie Brothers,
copyright Smithsonian Institution
Grown at Smithsonian Institution greenhouses
Another photo of this distinctive flower can be seen here. Note the distinction between what are apparently leafy calyces and the large orange bract from which other buds are emerging at the axil.
Other Drymonias with distinctively colorful calyces include D. strigosa and D. semicordata.