As a comment about Star Flower (Pentas lanceolata)
Pentas come as both upright plants reaching 3 to 4 feet in height, as well as dwarf varieties that attain a low, mounding form. In warm climates Pentas are fast growing, constantly blooming perennials. They are grown as annuals in northern areas. Pentas prefer full sun and are more prolific bloomers when in a sunny location, but they will also do fine in a partially shaded area of the garden, just with fewer blooms. Pentas attract both butterflies and hummingbirds.
Although I haven't noticed hummingbirds visiting the Pentas in my garden, they are absolute butterfly magnets! I've grown the white, light pink, dark pink and red varieties and the red is definitely my favorite!