4830 x 3217 px | 40,9 x 27,2 cm | 16,1 x 10,7 inches | 300dpi
Date de la prise de vue:
11 février 2009
Lieu:
County Durham , england
Informations supplémentaires:
The Asteraceae or Compositae (commonly referred to as the aster, daisy, or sunflower family), is an exceedingly large and widespread family of vascular plants. The group has more than 22, 750 currently accepted species, spread across 1620 genera and 12 subfamilies. Along with the Orchidaceae, this makes it one of the two largest flowering plant families in the world. However, selecting which of the two families is larger has yet to be been done conclusively, owing to the uncertainty around exactly how many species are in each group. The largest composite genera are Senecio (1, 000 species), Vernonia (1, 000 species), Centaurea (700 species), Cousinia (600 species), Helichrysum (550 species), and Artemesia (550 species). Most members of Asteraceae are herbaceous, but a significant number are also shrubs, vines and trees. The family is distributed throughout the world, and is most common in the arid and semi-arid regions of subtropical and lower temperate latitudes. Many economically important products come from composites, including cooking oils, lettuce, sunflower seeds, artichokes, sweetening agents, and teas. Several genera are also very popular with the horticultural community, these include marigolds, chrysanthemums, dahlias, zinnias, and heleniums. Daisies have a worldwide distribution, being found everywhere except Antarctica and the extreme Arctic. They are especially numerous in tropical and subtropical regions (notably Central America, eastern Brazil, the Andes, the Mediterranean, southern Africa, central Asia, and southwestern China). It is not affected by mowing and is therefore often considered a weed on lawns, though many also value the appearance of the flowers. Several cultivars and hybrids have been selected with much larger flower heads up to 5–6 cm diameter and with light pink to purple-red ray florets. Bellis perennis has astringent properties and has been used in folk medicine. In ancient Rome,
