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Bidens Discoidea
''Bidens discoidea'', the small beggarticks, is a North American species of flowering plant in the family Asteraceae. It is widespread across eastern Canada and the eastern and central United States, from Nova Scotia west to Minnesota, south to Florida and Texas. ''Bidens discoidea '' is an annual herb up to 180 cm (72 inches) tall. It produces as many as 3 flower heads containing orange disc florets but no ray florets. The species grows in marshes and other wet sites. as ''Coreopsis discoidea'' References External links Bidens, discoidea Flora of Northern America Plants described in 1842 {{Coreopsideae-stub ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torr
The torr (symbol: Torr) is a unit of pressure based on an absolute scale, defined as exactly of a standard atmosphere (). Thus one torr is exactly (≈ ). Historically, one torr was intended to be the same as one "millimeter of mercury", but subsequent redefinitions of the two units made them slightly different (by less than ). The torr is not part of the International System of Units (SI). It is often combined with the metric prefix milli to name one millitorr (mTorr) or 0.001 Torr. The unit was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644. Nomenclature and common errors The unit name ''torr'' is written in lower case, while its symbol ("Torr") is always written with upper-case initial; including in combinations with prefixes and other unit symbols, as in "mTorr" (millitorr) or "Torr⋅L/s" (torr-litres per second). The symbol (uppercase) should be used with prefix symbols (thus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |