Hydrophyllum appendiculatum, commonly known as great waterleaf, appendage waterleaf,[1] or woolen breeches,[2] is a species of plant in the Boraginaceae (borage) family. It is native to central and eastern North America where it is found primarily in the Midwest and Upper South of the United States. It is a biennial that produces lavender-colored flowers in late spring and early summer.[3]
H. appendiculatum is a biennial herbaceous plant that grows to a height of NaN0NaN0 with branching, hairy stems. The leaves are also hairy, alternate, and about NaN0NaN0 long and across. The lower leaves are longer than they are wide, and the middle and upper leaves are more rounded. All the leaves are cleft into 3 to 5 lobes.[3]
The inflorescence is a loose cluster, or cyme of pinkish purple or lavender flowers at the ends of the stems and branches rising above the leaves, NaN0NaN0 long. Each flower is NaN0NaN0 across.[4] The calyces have short, triangular appendages flaring away at the sinuses.[2]
This species can be distinguished from Hydrophyllum canadense, which has a similar appearance and broad geographical overlap, by the presence of small appendages in the sinuses of the calyx of H. appendiculatum. In addition, H. canadense and another similar plant, Hydrophyllum virginianum, have less hairy stems than H. appendiculatum.[3]
H. appendiculum is native to the United States from Nebraska and Kansas to the west, Mississippi and Alabama to the south, the Canadian border to the north, and New York to the east. In Canada, it is native to Ontario.[1] Its natural habitat is mesic calcareous forests, bottomland woods, bases of bluffs, quarries, and slopes.[2]
Flowers bloom May to July[5] and attract a variety of bees, flies, butterflies, and skippers.[3]