Amaranthus is a cosmopolitan genus of annual or short-lived perennial plants collectively known as amaranths. Some amaranth species are cultivated as leaf vegetables, pseudocereals, and ornamental plants. Catkin-like cymes of densely packed flowers grow in summer or autumn. Amaranth varies in flower, leaf, and stem color with a range of striking pigments from the spectrum of maroon to crimson and can grow longitudinally from 1 to 2.5 metres tall with a cylindrical, succulent, fibrous stem that is hollow with grooves and bracteoles when mature. There are approximately 75 species in the genus, 10 of which are dioecious and native to North America with the remaining 65 monoecious species endemic to every continent from tropical lowlands to the Himalayas. Members of this genus share many characteristics and uses with members of the closely related genus Celosia. Amaranth grain is collected from the genus. The leaves of some species are also eaten.
Pigweed can mean any of a number of weedy plants which may be used as pig fodder:
Amaranthus blitum, commonly called purple amaranth or Guernsey pigweed, is an annual plant species in the economically important plant family Amaranthaceae.
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbleweed is in effect the entire plant apart from the root system, but in other plants, a hollow fruit or inflorescence might detach instead. Xerophyte tumbleweed species occur most commonly in steppe and arid ecosystems, where frequent wind and the open environment permit rolling without prohibitive obstruction.
Amaranthus hybridus, commonly called green amaranth, slim amaranth, smooth amaranth, smooth pigweed, or red amaranth, is a species of annual flowering plant. It is a weedy species found now over much of North America and introduced into Europe and Eurasia.
Amaranthus caudatus is a species of annual flowering plant. It goes by common names such as love-lies-bleeding, pendant amaranth, tassel flower, velvet flower, foxtail amaranth, and quilete.
Amaranthus spinosus, commonly known as the spiny amaranth, spiny pigweed, prickly amaranth or thorny amaranth, is a plant that is native to the tropical Americas, but is present on most continents as an introduced species and sometimes a noxious weed. It can be a serious weed of rice cultivation in Asia.
Amaranthus retroflexus is a species of flowering plant in the family Amaranthaceae with several common names, including red-root amaranth, redroot pigweed, red-rooted pigweed, common amaranth, pigweed amaranth, and common tumbleweed.
Amaranthus palmeri is a species of edible flowering plant in the amaranth genus. It has several common names, including carelessweed, dioecious amaranth, Palmer's amaranth, Palmer amaranth, and Palmer's pigweed.
Species belonging to the genus Amaranthus have been cultivated for their grains for 8,000 years. Amaranth plants are classified as pseudocereals that are grown for their edible starchy seeds, but they are not in the same botanical family as true cereals, such as wheat and rice. Amaranth species that are still used as a grain are Amaranthus caudatus L., Amaranthus cruentus L., and Amaranthus hypochondriacus L. The yield of grain amaranth is comparable to that of rice or maize.
Amaranthus blitoides, commonly called mat amaranth, prostrate pigweed, procumbent pigweed, prostrate amaranth, or matweed, is a glabrous annual plants species. It usually grows up to 0.6 m, though it may grow up to 1 m. It flowers in the summer to fall.
Amaranthus deflexus is also known by the common names low amaranth, Argentina amaranth, perennial pigweed, and large-fruit amaranth. It is native to South America, and has been introduced to many other parts of the world. It is a short-lived perennial or annual plant. The plant can grow up to 1.5 ft in height.
Amaranthus graecizans, the Mediterranean amaranth or short-tepalled pigweed, is an annual species in the botanical family Amaranthaceae. It is native to Africa, southern Europe, East Asia to India and Central Asia. It is naturalized in North America. More general common names include tumbleweed and pigweed.
Cycloloma is a monotypic genus which contains the sole species Cycloloma atriplicifolium, which is known by the common names winged pigweed, tumble ringwing, plains tumbleweed, and tumble-weed. This plant is native to central North America, but it is spreading and has been occasionally reported in far-flung areas from California to Maine to the Canadian prairie. It is considered an introduced species outside of central North America. This is a bushy annual herb forming a rounded pale green clump which may exceed 0.5 m in height. It is very intricately branched, with toothed leaves occurring near the base. The spreading stems bear widely spaced flowers are small immature fruits fringed with a nearly transparent membranous wing. In autumn, the plant forms a tumbleweed. The fruit is a utricle about 2 millimeters long containing a single seed.
Atriplex hortensis, known as garden orache, red orache or simply orache, mountain spinach, French spinach, or arrach, is a species of plant in the amaranth family used as a leaf vegetable that was common before spinach and still grown as a warm-weather alternative to that crop. For many years, it was classified in the goosefoot family, but it has now been absorbed into the Amaranthaceae. It is Eurasian, native to Asia and Europe, and widely naturalized in Canada, the United States, Australia, and New Zealand.
Amaranthus powellii is a species of amaranth known by the common names Powell's amaranth and green amaranth.
Amaranthus watsonii is a species of amaranth known by the common name Watson's amaranth. It is native to the southwestern United States and northern Mexico, where it grows in sandy places such as deserts and beaches, and disturbed areas. It is also known as a rare introduced species in parts of Europe. This is an erect annual herb producing a glandular hairy stem to a maximum height of about a meter. The leaves are generally oval-shaped and up to 8 centimeters long, with a petiole of up to 9 centimeters. The species is dioecious, with male and female individuals producing different types of flowers. The inflorescence is a long spike cluster of flowers interspersed with spiny green glandular bracts. The fruit is a smooth capsule about 2 millimeters long that snaps in half to reveal a small shiny reddish black seed.
Scleranthus annuus is a species of flowering plant in the family Caryophyllaceae known by the common names German knotweed and annual knawel. It is native to Europe, Asia, and North Africa, and it is known throughout the rest of the temperate world as an introduced species and a common weed. It grows in many types of habitat, often in disturbed areas.
Trianthema portulacastrum is a species of flowering plant in the ice plant family known by the common names desert horsepurslane, black pigweed, and giant pigweed. It is native to areas of several continents, including Africa and North and South America, and present as an introduced species in many other areas. It grows in a wide variety of habitat types and it can easily take hold in disturbed areas and cultivated land as a weed.
