Baptisia tinctoria (L.) R. Br. ex Ait. f.
Yellow Wild Indigo
Habitat: Dry open woods and clearings. [Dry barrens (partly forested, upland); Hardwood to mixed forest (forest, upland)]
Range: Maine to Vermont, Ontario, Minnesota, south to Florida and Louisiana.
Aids to Identification: Wild indigo grows 0.3-1 m high, with much-branched stems which bear compound leaves with rounded leaflets. Elongate clusters of showy, yellow pea-like flowers appear at the ends of the branches. The stipitate ovary and smaller leaflets distinguish this from the introduced Thermopsis mollis.
Ecological characteristics: Wild indigo is an herbaceous perennial which grows in sandy, open areas primarily to the south of Maine. It derives its name from the bluish-black dye which can be extracted from the plant.
Phenology: Flowers in July.
Synonyms: Baptisia tinctoria (L.) R. Br. ex Ait. f. var. crebra Fern.; Baptisia tinctoria (L.) R. Br. ex Ait. f. var. projecta Fern.
Known Distribution in Maine: This rare plant has been documented from a total of 3 town(s) in the following county(ies): York.
Reason(s) for rarity: Reaches its northern limit in Maine.
Conservation considerations: The one known population occurs near a road where it could be affected by road maintenance activities; but plants along the road are more vigorous than those in the adjacent woods, suggesting that forest succession may be causing the species to decline.