Oclemena nemoralis, commonly known as bog aster or bog nodding-aster, is a species of flowering plant in the aster family Asteraceae. It is native to northeastern North America. It is one of the parent species of the hybrid known as Blake's aster.
Oclemena nemoralis is a perennial, herbaceous plant that propagates via a swollen tuber at the tip of a slender, elongated rhizome. It stands tall with 30âÂÂ100 leaves uniformly distributed along the stem, each leaf 1âÂÂ8 mm wide. The leaf margins are entire (or nearly so) and revolute. It can have as many as 15 flower heads (nodding in bud) but it usually has a single flower head borne on a thread-like peduncle long. A flower head has 13âÂÂ25 ray flowers, pink to purple (seldom white), and 20âÂÂ35 disc flowers.
Oclemena nemoralis is closely related to Oclemena acuminata. Hybrid populations can occur wherever the parent species come in contact, that is, at the forest-bog ecotone. The hybrid is known as Blake's aster.
Oclemena nemoralis was first described as Aster nemoralis by the Scottish botanist William Aiton in 1789. The American botanist Edward Lee Greene transferred Aster nemoralis to genus Eucephalus in 1896, but Greene transferred it again in 1903, this time to genus Oclemena. , the botanical name Oclemena nemoralis is widely accepted.
Oclemena nemoralis is native to eastern Canada and northeastern United States:
Throughout most of its range, Oclemena nemoralis has adapted to acidic sphagnum bogs but in the eastern Upper Peninsula of Michigan, it prefers fen habitat.
, Oclemena nemoralis is globally secure (G5). Its conservation status in Canada is also secure. However, it is uncommon (S3) in Prince Edward Island, Michigan, and New York; imperiled (S2) in Rhode Island and Vermont; and both critically imperiled (S1) and endangered in Connecticut and Pennsylvania. It is presumed to be extirpated (SX) in Delaware.
The Ojibwe use a decoction of root as drops or on a compress for sore ears.