Buchnera americana is a perennialflowering plant with underground rhizomes and an above-ground stem. The stem of the plant is usually covered with trichomes, and can grow tall. The leaves are opposed, meaning that they grow in pairs, sprouting directly across from each other. It blooms all year round, but the flowers are at their peak between June and September. During the remaining months of the year, the petals darken and dry up. The flower of Buchnera americana is a light purple dicot. Its fruits are dark purple and form in capsules in length.
Distribution and habitat
Bluehearts are found in 12 states, ranging from Ohio to Florida. They are most common in Missouri and Tennessee, where they are abundant in moist environments. The plant also occurs in a small area of south-western Ontario from Lake Huron. Buchnera americana is mostly found along the edges of wet depressions, in limestone glades, prairies, moist sandy soils, and open woods. It sometimes forms a hemiparasitic relationship with a tree, by attaching itself to the root system.
Conservation
In Canada, Buchnera americana is only found in "a stretch of the shoreline of Lake Huron in South-western Ontario". Only six populations exist, and they are considered Endangered provincially and nationally. In the United States, bluehearts are found in 11 states, from Ohio and Indiana to Georgia and Missouri. They are state ranked from S1 to S5 according to their degree of occurrence: S1 is extremely rare and S5 is secure. In Georgia and Virginia bluehearts are listed as S1; they are listed as S2 in Ohio and Texas; they are listed as S3 in Illinois, Kansas, Tennessee and parts of Kentucky; they are listed as S4 in Arkansas, Missouri and parts of Kentucky. In Ontario their natural interdunal habitats are threatened by development for housing, cottages and recreational areas, such as parks where the flowers are stepped on or picked. In the United States, bluehearts live in prairie habitats where fire is a necessary disturbance for seed germination and growth of other plants, but detrimental to bluehearts. Since burning occurs in a rotational 3–4 year cycle in Indiana, Illinois, Missouri and Ohio, Bluehearts are greatly affected by habitat loss in these areas of the United States.
Ecological importance
Bluehearts are hemiparasitic, meaning they are able to grow independently without a host but grow more strongly with a host. They attach to their host plant by parasitic roots called haustoria. During stressful conditions, bluehearts may heighten their parasitic effects to the point where a large group of them may damage small trees. Common host trees of bluehearts are white oak, eastern white pine, green ash, and cottonwood. Caterpillars of the common buckeye feed on the blueheart.
Uses
Buchnera americana has no known medicinal uses. In the garden, this plant is highly attractive to bees, butterflies, and birds.
