The dogbane is a North American plant which has bell-shaped white and pink flowers. Plants with bell-shaped flowers are from the genus Apocynum.
The plant you are thinking of is the bellflower or campanula. There are 500 varieties of it. Or another possibility is lily of the valley. There are both white and pink versions.
Dogbane
Adams-Needle
Rudbeckia
rudbeckia
Rudbeckia
Rudbeckia, sunflowers and daisies have golden ray-like flowers and are cultivated in North America.
Adams Needle or Yucca filamentosa
North American Plant Protection Organization was created in 1976.
herb bennet
Godetias
One common North American plant of the genus Rudbeckia is the black-eyed Susan (Rudbeckia hirta). This perennial plant is known for its bright yellow flowers with dark centers, resembling a black eye. It is a popular choice in gardens and is also native to parts of Canada and the United States.
agave
An achimenes is a Central American plant of the genus Achimenes, with trumpet-shaped flowers.