Oclemena nemoralis

Oclemena nemoralis
Hamilton County, New York in August
Conservation status
Secure  (NatureServe) [1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Oclemena
Species:	O. nemoralis
Binomial name
Oclemena nemoralis (Aiton) Greene [2]
Synonyms [3]
Homotypic synonyms Aster nemoralisAiton Eucephalus nemoralis(Aiton) Greene Heterotypic synonyms Aster greeniiNees ex Torr. & A.Gray Aster ledifoliusPursh Aster ledifolius var. uniflorusPursh Aster nemoralis f. albiflorusFernald Aster uniflorusMichx. Galatella nemoralisNees Galatella nemoralis var. monocephalusDC. Galatella nemoralis var. uniflora(Pursh) Hook. Matricaria americanaMill.

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.

Description

Oclemena nemoralis is a perennial, herbaceous plant that propagates via a swollen tuber at the tip of a slender, elongated rhizome. It stands 5–70 cm (2–28 in) tall with 30–100 leaves uniformly distributed along the stem, each leaf 1–8 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 3–7 cm (1.2–2.8 in) long. A flower head has 13–25  ray flowers, pink to purple (seldom white), and 20–35  disc flowers. ^{[4] [5] [6]}

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.

Taxonomy

Oclemena nemoralis was first described as Aster nemoralis by the Scottish botanist William Aiton in 1789. ^[7] The American botanist Edward Lee Greene transferred Aster nemoralisAiton to genus Eucephalus in 1896, ^[8] but Greene transferred it again in 1903, this time to genus Oclemena. ^[2] As of December 2025 ^[update] , the botanical name Oclemena nemoralis(Aiton) Greene is widely accepted. ^{[3] [9] [10] [11]}

Distribution and habitat

In flower and bud in Nova Scotia in July

Oclemena nemoralis is native to eastern Canada and northeastern United States: ^{[3] [6]}

• Canada: New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Prince Edward Island, Quebec
• United States: Connecticut, Delaware, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont
• Other: Saint Pierre and Miquelon

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. ^[12]

Conservation

As of December 2025 ^[update] , Oclemena nemoralis is globally secure (G5). ^[1] 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. ^{[13] [14]} It is presumed to be extirpated (SX) in Delaware. ^[15]

Uses

The Ojibwe use a decoction of root as drops or on a compress for sore ears. ^[16]

References

1. NatureServe (5 December 2025). "Oclemena nemoralis". NatureServe Explorer. Arlington, Virginia. Retrieved 7 December 2025.
2. "Oclemena nemoralis(Aiton) Greene". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 6 December 2025.
3. "Oclemena nemoralis(Aiton) Greene". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 7 December 2025.
4. Greene (1903).
5. Nesom (1995), pp. 175–178.
6. Brouillet, Luc (2006). "Oclemena nemoralis". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 20. New York and Oxford: Oxford University Press. Retrieved 9 December 2025– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
7. "Aster nemoralisAiton". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 7 December 2025.
8. "Eucephalus nemoralis(Aiton) Greene". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 7 December 2025.
9. "Oclemena nemoralis(Aiton) Greene". WFO Plant List. Retrieved 8 December 2025.
10. NRCS. "Oclemena nemoralis". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 8 December 2025.
11. "Oclemena nemoralis(Aiton) Greene". Database of Canadian Vascular Plants. Retrieved 8 December 2025.
12. Reznicek, A. A.; Voss, E. G.; Walters, B. S. (February 2011). "Oclemena nemoralis(Aiton) Greene". Michigan Flora Online. University of Michigan. Retrieved 6 December 2025.
13. "Endangered, Threatened, and Special Concern Plants". Connecticut Department of Energy and Environmental Protection. Retrieved 9 December 2025.
14. "Pennsylvania Vascular Plant List". Pennsylvania Department of Conservation and Natural Resources. Retrieved 9 December 2025.
15. McAvoy, William A. (2024). "Rare and Uncommon Plants of Delaware" (PDF). Delaware Department of Natural Resources and Environmental Control. Retrieved 9 December 2025.
16. Densmore, Frances, 1928, Uses of Plants by the Chippewa Indians, SI-BAE Annual Report #44:273-379, page 360

Bibliography

• Greene, Edward Lee (1903). "Further Segregates from Aster". Leaflets of Botanical Observation and Criticism. 1: 4–7. Retrieved 10 December 2025.
• Nesom, Guy L. (1995). "Review of the taxonomy of Aster sensu lato (Asteraceae: Astereae), emphasizing the new world species". Phytologia. 77 (3): 141–297. Retrieved 10 December 2025.

External links

• "Oclemena nemoralis(Aiton) Greene". Global Compositae Database. Compositae Working Group (CWG). 2025. Retrieved 10 December 2025.