Sunday, 19 June 2016

Phytolacca americana

American pokeweed (Phytolacca americana), or simply pokeweed, is a
herbaceous perennial plant in the pokeweed family Phytolaccaceae growing up to 8 feet (2 meters) in height. It is native to the eastern United States and has significant toxicity.

It has simple leaves on green to purplish stems and a large white taproot. The flowers are green to white, followed by purple to almost black berries which are a food source for songbirds such as gray catbird, northern mockingbird, northern cardinal, and brown thrasher, as well as other birds and some small animals (i.e., to species that are unaffected by its mammalian toxins).

Phytolacca. americana or pokeweed—also known by a number of other names—is native to eastern North America, the Midwest, and the Gulf Coast, with more scattered populations in the far West. It is considered a major pest species by farmers, and that and the danger of human poisoning—its significant toxicity and its risks to human and animal health are consistently reported, with the whole of the plant toxic and increasing in toxicity through the year, with children at particular risk of its very poisonous purple-red ripe fruit—support arguments for eradication of P. americana. Even so, it is used as an ornamental in horticulture, and it provokes interest for the variety of its natural products (toxins and other classes), for its ecological role, its historical role in traditional medicine, and for some utility in biomedical research (e.g., in studies of pokeweed mitogen). In the wild, it is easily found growing in pastures, recently cleared areas, and woodland openings, edge habitats such as along fencerows, and in waste places.

Bearing toxicity information in mind (see section above), nutritional information for boiled and drained pokeberry shoots has been reported (see box).

Bearing toxicity information in mind (see section above), nutritional information per 100 grams dry weight of shoots has been reported:

Protein: 31 g; fat: 4.8 g; carbohydrates: 44 g; fiber: 0 g; ash: 20.2 g
Minerals - calcium: 631 mg; phosphorus: 524 mg; iron: 20.2 mg; magnesium: 0 mg; sodium: 0 mg; potassium: 0 mg; zinc: 0 mg
Vitamins - vitamin A: 62 mg; thiamine (vitamin B1): 0.95 mg; riboflavin (vitamin B2): 3.93 mg; niacin (vitamin B3): 14.3 mg; vitamin B6: 0 mg; vitamin C: 1619 mg

Pokeweed is a member of the Phytolaccaceae, or broader pokeweed family, and is a native herbaceous perennial plant, that is large, growing up to 8 feet (2 meters) in height. One to several branches grow from the crown of a thick, white, fleshy taproot, each a "stout, smooth, green to somewhat purplish stem;" with simple, entire leaves with long petioles alternately arranged along the stem.

Pokeweeds reproduce only by its seeds (large glossy black, and lens-shaped), contained in a fleshy, 10-celled, purple-to-near-black berry with crimson juice. The flowers are perfect, radially symmetric, white or green, with 4-5 sepals and no petals. The flowers develop in elongated clusters termed racemes. The seeds have a long viability and can germinate after many years in the soil.

Birds are unaffected by the natural chemicals contained in the berries (see below), and eat them, dispersing the seeds. Seed are also found in commercial seed (e.g., vegetable seed packets). The berries are reported to be a good food source for songbirds and other bird species and small animals unaffected by its toxins. Distribution via birds is thought to accounts for the appearance of "single, isolated plants" in areas that had otherwise not been populated by pokeweed.

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