Oclemena acuminata [Michaux] Greene
The words or terms in red
(actually dark orange) in the text are defined in a
Oclemena acuminata also known as
is a native perennial of North America.
The plant belongs to the
In Greek, αστηρ (aster)
means star, and the name refers then to the shape of the flower head.
In Latin, acuminatus means pointed,
refers then to the pointed tip of the leaves.
As for the Oclemena genus name, neither my Gaffiot Latin to French
dictionary nor my Bailly classical Greek to French dictionary gave me any clue.
Some of the vernacular names of
Oclemena acuminata (Aster acuminatus) are:
Whorled Aster, Whorled Wood Aster, Sharpleaf Aster,
White Wood Aster, Sharp-leaved Aster or White Woodland Aster.
(In French: Aster à rameaux étalés, Aster acuminé).
Oclemena acuminata has also been known as:
- Aster acuminatus Michaux
- Aster acuminatus Michaux var. magdalenensis Fernald
- Aster divaricatus Lamark
Oclemena acuminata is conspicuous when in bloom and unlikely to be
overlooked or misidentified.
This is a unique aster that is very easy to identify by the unusual combination
of running rhizome,
leaves with sharply toothed outer
margins, and few large flowers.
The somewhat similar species are the Aster macrophyllus
and Aster umbellatus; but Aster macrophyllus
(Large-leaved Aster) has very large basal leaves and
Aster umbellatus (Flat-topped White Aster) has quite narrower leaves.
A usually short plant, one of the few woodland species.
It spreads by running rhizomes in the lower forest floor
or upper mineral soil.
- Height: 1 to 3 feet.
- Hairy , finely
- Often in zigzag.
- Sometimes reddish at the base.
- Arranged alternately or rather spirally around the stem
but appear to be in a whorl.
- Upper leaves are larger than lower leaves.
- No Leaves on the lower part of the stem.
- Coarsely toothed with few teeth in the upper half.
- Long-pointed at both ends.
- Around 6 cm long and 2 cm wide.
- With a viscid (sticky) underside.
in a globular cluster
held loosely at top of plant.
- Ray flowers (petals)
not straight like other asters.
- 1 to 1.5 inch wide.
- Ray flowers: white or purple-tinged.
- Yellow reddish disk flowers (center)
that turn red to purplish once
- Blooming from July to October, often the
earliest aster to bloom.
- Flowering is much more abundant on plants in open areas.
- Fruiting from August to October.
Achenes around 3 mm long, 1/2 mm wide.
- With copious glands on the achenes.
- Pappus white, around 6 mm long.
Wooded areas, clearings.
forest, especially on acidic substrates.
An occasional species on the watershed,
of wet openings along stream on dip slope.
Apt to be found in open patches since it is a light loving species.
Oclemena acuminata is a plant of eastern North America.
It is found in eastern Canada, from Nova Scotia and Québec to eastern Ontario.
In eastern USA it is found from Ohio in the west to New England in the east,
and southward to Georgia and Tennessee, also further south in the mountains.
The map shows the USA States and Canadian provinces
where the plant can be found.
The photos of the gallery were taken either with one of the following:
The title in the window shows the date when the picture was taken,
i.e. jan_30_06... would mean that the photo was taken on the 30th of
January, the 06 is for the 6th picture taken that day.
- Fuji Mx 700.
- Minolta DiMAGE 7.
- Nikon 2200.
- EPSON Perfection 1650 scanner.
The month, day and picture number might be followed by a letter:
and if there is no letter it's obviously the Minolta.
- f for the Fuji.
- n for the Nikon.
- s for the EPSON scanner.
Click on the thumbnails to get larger view.
The original usually photos are in TIFF format,
the photos shown are in JPEG format,
usually of dimension one half (surface one quarter) for loading time reduction.
Flowers, leaves and seeds
The leaves were scanned at 300 dpi, and the image dimensions reduce by half
(one quarter in surface). The cent with the achenes and pappus gives the
dimensions of the seed.