Flower:

Flat to round clusters up to 4 inches across of tiny trumpet shaped flowers. Flowers are pinkish to white, up to ¼ inch long with five round lobes; 3 creamy white stamens poke out of the tube. A plant may have multiple clusters on branching stems in the upper plant.

Leaves and stems:

The opposite, compound leaves are up the 8 inches long, each with 7-12 pairs of narrow lance-shaped, toothed leaflets with scattered hairs on lower surface. Leaves become smaller and leaflets become narrower as they ascend the stem. Stems are finely hairy, especially at nodes.

Fruit:

Fruit is a brown seed, about 1/8 inch long, with an array of feathery hairs radiating at the top.

Notes:

Garden Heliotrope is a good example of how foreign invasive species typically exist for many decades in small isolated pockets. Population expansion is cryptic to casual observers until it suddenly becomes exponential and it starts showing up everywhere. Landowners and resource managers can expect this to become a frequent management problem in the near future while common backyard gardeners will have no notion that they are the source of the invasion. It is now becoming quite common on roadsides along the north shore of Lake Superior and will only get worse with time. The Wisconsin DNR recognized the potential threat this species presented back in the 1990s, and Connecticut has seen fit to ban it altogether.

While doing research on this species, I came across claim after claim of how beneficial it is to pollinators, but it is simply another nectar source—sugar water would do just as well, along with countless native species that provided nectar long before this plant ever arrived here. I have not found any account of Garden Heliotrope being a host plant for any native insects. Reading various gardeners' blogs, at first I found it interesting how excited they'd get when this wonder plant started spreading into all corners of their gardens. But this discourages me, as it demonstrates both the invasive nature of the beast, and the blindness of the average gardener to the invasive behavior.