| Oclemena | |
|---|---|
| |
| Oclemena nemoralis (Bog-aster) | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Subfamily: | Asteroideae |
| Tribe: | Astereae |
| Subtribe: | Oclemininae G.L.Nesom |
| Genus: | Oclemena Greene |
| Synonyms | |
| |
Oclemena is a small genus of North American flowering plants in the tribe Astereae within the family Asteraceae.[1][2]
It is native to northeastern North America, found in wet or dry woodlands, and sometimes in clearings in the woods, or in acid bogs and peat.[3]
The finely woolly stem grows in a zig-zag fashion to a height 30–100 cm (1–3 ft). It may be red at its base.[3]
The lanceolate leaves are numerous, arranged in a spiral whorl around a single stem. They can be sharply toothed along the margin (as in O. acuminata) or smooth (as in O. nemoralis). The leaves contain sessile resin glands.[3]
The flower heads consist of flat-topped pink to rose-violet ray florets and yellow disk florets. There are one to a few on a plant, growing on a slender peduncle. The disk flowers are abruptly expanded at the top. The scarious floral bracts consist of narrow chlorophyllous bands, tinted with purple along the midrib.[3]
The stipitate ovaries are generally compressed and show on the surface minute, cylindrical glands. The fruit is a glandular achene with a double pappus of two bristled whorls.[3]
The chromosome base number is x=9.
The Kew database Vascular Plant Families and Genera categorizes Oclamena under the genus Aster L. But taxonomically, Oclemena belongs to the North American clade of the tribe Astereae, as a basal member of one of the main branches.[4]
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Whorled Wood Aster (Oclemena acuminata) -
Bog Aster (Oclemena nemoralis)
- Oclemena acuminata (Michx.) Greene: Whorled wood aster, sharpleaf aster, white wood aster GA TN NC WV VA OH PA NJ DE NY CT RI MA VT NH ME NS NB QUE ONT NFL LAB
- Oclemena × blakei (Porter) G.L.Nesom (O. acuminata × O. nemoralis) : Blake's aster MI PA NJNY CT RI MA VT NH ME NS NB QUE ONT
- Oclemena nemoralis (Ait.) Greene: bog aster, bog nodding aster. MI DE MD PA NJ NY CT RI MA VT NH ME NS NB QUE ONT
- Oclemena reticulata (Pursh) G.L.Nesom: pinebarren whitetop aster. FL GA AL SC
- ^ Greene, Edward Lee. 1903. Leaflets of Botanical Observation and Criticism 1(1): 4–5 in English
- ^ Tropicos, Oclemena Greene
- ^ a b c d e Flora of North America Vol. 20 Page 78 Oclemena Greene
- ^ Brouillet, L., G.A. Allen, J.C. Semple, and M. Ito. 2001. ITS phylogeny of North American asters (Asteraceae: Astereae). Abstract. Botany 2001, August 2001. Albuquerque, N.M.
- ^ Flann, C (ed) 2009+ Global Compositae Checklist
- ^ The Plant List, search for Oclemena
- ^ Biota of North America Program 2013 county distribution maps