Mayweed

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Matricaria is a genus of flowering plants in the sunflower family (Asteraceae). Some of the species have the common name of "mayweed," but this name also relates to plants not in this genus.

Most are very common in the temperate regions of Europe, Asia, and America as well as in North Africa, and South Africa and some are naturalised in Australia. M. occidentalis is native in North America; other species are introduced.

These are hardy, pleasantly aromatic annuals, growing along roadsides, in ruderal soils, and fallow land, rich in nutrients. Many are considered nuisance weeds. However they are suitable for rock gardens, herb gardens and as border plants.

Their many-branched stems are prostrate to erect, glabrous and very leafy. Their bipinnate leaves have numerous linear, narrowly lobed leaflets.

The flowers are radially symmetrical.The greenish yellow capitula are semi-spherical. The white ray florets can be present (M. recutita) or lacking (M. discoidea). The disc florets are 4- to 5-dentate. The receptacle is 2-3 times as high as wide. The pappus may be crown-shaped and short, or lacking.

The extracts of German Chamomile (M. recutita) are taken as a strong tea, safe for human consumption. It has been ascribed in herbal medicine to be carminative and anti-inflammatory. It is also used in ointments, lotions, and as a mouthwash against infections of mouth and gums.

The taxonomy of Matricaria is controversial and very confused. Several species are classified in Tripleurospermum or Matricaria, depending on the interpretation of the author. The distinction is made according to the number of the seed ribs : Tripleurospermum has one adaxial and two lateral seed ribs, while Matricaria has 4 or 5 adaxial seed ribs.

Species

• Matricaria acutiloba
• Matricaria albida
• Matricaria arabica
• Matricaria arlgirdensis
• Matricaria auriculata
• Matricaria brachyglossa
• Matricaria burchellii
• Matricaria capitellata
• Matricaria confusa
• Matricaria conoclinia
• Matricaria coreana
• Matricaria corymbifera
• Matricaria courrantiana: Crown Mayweed
• Matricaria decipiens
• Matricaria dichotoma
• Matricaria discoidea : Disc Mayweed
• Matricaria fuscata
• Matricaria glabra
• Matricaria glabrata
• Matricaria globifera
• Matricaria grandiflora
• Matricaria heterocarpa
• Matricaria hirsutifolia
• Matricaria hirta
• Matricaria hispida
• Matricaria inodora
• Matricaria intermedia
• Matricaria lamellata
• Matricaria lasiocarpa
• Matricaria laxa
• Matricaria macrotis
  • Matricaria maritima f. coronata
  • Matricaria maritima ssp. phaeocephala
• Matricaria matricarioides : Pineapple Weed; Rounded Chamomile
• Matricaria melanophylla
• Matricaria microcephala
• Matricaria nigellifolia
• Matricaria occidentalis : Valley Mayweed
• Matricaria otaviensis
• Matricaria perforata : Scentless Mayweed
• Matricaria pinnatifida
• Matricaria praecox
• Matricaria recutita : Scented Mayweed, Wild Chamomile
• Matricaria raddeana
• Matricaria rosella
• Matricaria schinzinna
• Matricaria spathipappus
• Matricaria subglobosa
• Matricaria suffruticosa
• Matricaria trichophylla
• Matricaria tridentata
• Matricaria tzvelevii

See also

• Chamomile