eastern bluestar amsonia tabernaemontana var. salicifolia whitish-blue star-d flower

american amsonia apocynaceae blue bluestar botanical cultivar dogbane eastern endemic family flora flower flowers habitat hybrid inflorescence natural north perennial plant rarity salicifolia starshaped tabernaemontana var variety whitishblue wild willow woodland whitish-blue star-shaped apocynaceae high resolution wildflower habitat