Red, orange, and pink tubular flowers are most attractive to Ruby-throated Hummingbirds. It’s no coincidence that these flowers have a shape that fits a hummingbird’s bill well, since hummingbirds and certain flowers have co-evolved to benefit each other. The flowers attract the hummingbirds so they will transfer pollen from plant to plant, and the hummingbirds carry out that pollination while feeding themselves. Read the Hummingbirds: Jewelled Messengers movie review.
So, which native plants specifically? Eastern columbine (Aquilegia canadensis) is a great early bloomer that fits the bill, literally and figuratively. Bee balm (Monarda didyma) is a mid-summer bloomer that hummingbirds love. (Bee balm may seem like more of a puffy ball, but if you look at the flower head closely, it is composed of a cluster of many small, tubular, individual flowers.) Cardinal flower or red lobelia (Lobelia cardinalis) is another to consider, along with blazing star (Liatris spicata). Obedient plant (Physostegia virginiana) is a late summer bloomer that can persist into fall.
Although these are the classic hummingbird attractors, hummers will feed on other plants as well. Virginia bluebells (Mertensia virginica) are useful early-season flowers, and great blue lobelia (Lobelia siphilitica) is a mid- to late-summer option. Penstamons (Penstemon digitalis and other native Penstamons), which may be white or pale pink, also work. Garden phlox (Phlox paniculata) flowers are not tubular, but hummingbirds seem to like them.