Ligusticum genus --- parsley family

fernleaf licorice-root (Ligusticum filicinum) -- in July -- Yellowstone National Park, WY    ​white & cream 

Gray's licorice-root (Ligusticum grayi) -- in July -- Modoc National Forest, CA        white & cream  ​

osha (Ligusticum porteri) -- in July -- Crown Point, Roosevelt National Forest, CO       white & cream     

osha (Ligusticum porteri) -- in August -- Snowy Range, Medicine Bow National Forest, WY      white & cream       

osha (Ligusticum porteri) -- in September -- Cloudcroft, Lincoln National Forest, NM         white & cream  ​  ​   

slender ligusticum (Ligusticum tenuifolium) -- in July -- McCullough Gulch, Summit County, CO           white & cream