Matricaria discoidea de Candolle
The words or terms in red
actually dark orange) in the text are defined in a
commonly known as the pineapple weed
is a low growing annual plant
native to northwestern North America and
the north-east of Asia (It is possible that this plant was originally brought
to North American from NE Asia by Amerindians). It has spread to eastern and
northern North America and has become a
The root system consists of a branching
Matricaria discoidea can grow in dense mats in the well trodden areas.
It is aromatic, with a pineapple odor when bruised. Its number of
chromosomes (2n) is 18.
The species belongs to the
In Latin, one of the meanings of matrix is the womb; the name
Matricaria was given to the genus because Matricaria recutita
(the chamomile) was widely used to treat such gynecologic complaints as
menstrual cramps and sleep disorders related to premenstrual syndrome.
Matricaria recutita has been found to contain fairly strong
antispasmodic and anti-inflammatory constituents and is particularly effective
in treating stomach and intestinal cramps.
In classical Greek,
(diskoeidês) means discoid
(shaped like a disk) a term that is derived from
(diskos) that means
disk and from
(eidos) that means shape, external aspect.
The epithet refers then to the
Matricaria discoidea that are without rays, i.e.
Some of the vernacular names of
Matricaria discoidea are
Pineappleweed, Pineapple Weed, Disc Mayweed, Rayless chamomile.
The French vernacular name are Matricaire odorante, Matricaire sans
ligules, Matricaire fausse-camomille, Matricaire parfumée, Matricaire en
Matricaria discoidea has also been known as:
- Artemisia matricarioides Less.
- Chamomilla suaveolens (Pursh) Rydb.
- Lepidanthus suaveolens (Pursh) Nutt.
- Lepidotheca suaveolens (Pursh) Nutt.
- Matricaria matricarioides (Less.) Porter
- Matricaria suaveolens (Pursh) Buchenau, non L.
- Santolina suaveolens Pursh
- Tanacetum suaveolens (Pursh) Hook.
Matricaria discoidea is easy to identify by its highly dissected foliage,
its small size, its greenish-yellow flower heads without
ray florets and the pineapple scent of its
foliage. It cannot be confused with Matricaria chamomilla that is also
found in Québec, since the later one has white rays florets while the former
- Up to 10 cm high.
- Usually erect or ascending,
- Leafy and smooth.
- Branched from bases.
- A bit fern-like, one to three times
dissected into very narrow linear to
- Up up to 2 inches long and 3/4 inch across.
- Sweet-scented when crushed.
- Usually borne singly, from the
axils of the upper leaves,
sometimes in open, corymbiform
- Between 0.5 to 1 cm wide.
- Lacking ray florets.
- With from 100 to 500 greenish yellow
- With 3 series of phyllaries.
- With a short peduncle.
- Blooming from early summer to the fall in my area,
25 km north of Montréal.
- A pale brown to tan oblong cypsela.
- With a short coroniform pappus.
Matricaria discoidea natural habitat is ill-defined because the species
has become ruderal even in its native range.
It grows well in disturbed areas, especially those with poor, compacted soil.
It can be seen blooming on footpaths, roadsides, cultivated and abandoned
fields and gardens, irrigation ditches, stream banks, and similar places.
It grows best in full sun.
Matricaria discoidea is found in all the Canadian provinces nearly all
the Canadian Territories; it is also found in nearly all states in the USA,
including Alaska, but for Florida, Alabama and Georgia.
The maps shows the worldwide distribution of the plant. (One of the synonyms of
Matricaria discoidea is Chamomilla suaveolens).
The flowers of Matricaria discoidea exude a chamomile or pineapple
aroma when crushed. They are edible and have been used in salads (although they
may become bitter by the time the plant blooms) and to make a herbal tea.
Matricaria discoidea has also been used for medicinal purposes,
including for relief of gastrointestinal upset, infected sores, fevers,
and postpartum anemia.
It was often used by the American Indians, at times as a panacea.
The Aleut (from the Aleutian Islands) used an infusion of the leaves
for stomach pains, especially from gas, and as a
laxative and a
The Blackfoot and Cahuilla used a decoction of the plant and flowers for
The Cheyenne used it in their Sun Dance ceremony and as an
ingredient in many medicines. The Eskimo used the plant in steambath for its
pleasant odor and for medicinal purposes. The Montana Indians used an
infusion of herb for building up blood at childbirth and delivering the
placenta, and for young girls for menstrual cramps. Etc.
Matricaria discoidea is closely related to plants of the Ambrosia
genus (ragweed, and can cause similar allergic reactions in susceptible
The photos of the gallery were taken either with one of the following:
Minolta DiMAGE 7,
Canon PowerShot A530,
Canon Xt Rebel, usually with the EF-S60mm f/2.8 Macro USM objective,
Fujifilm A 610 and
EPSON Perfection 1650 (scanner).
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.
The month, day and picture number might be followed by a letter which I use
to identify the system used to take the picture.
Click on the thumbnails to get larger view.
The original photos are usually in TIFF format,
the photos shown are generally in JPEG format,
often of dimensions one half (surface one quarter)
for loading time reduction.