What is Heliantheae?
{{taxobox |name = Heliantheae |image = |image_caption = Sunflowers have bright yellow flowers. |regnum = [[Plantae]] |unranked_divisio = [[Angiosperms]] |unranked_classis = [[Eudicots]] |unranked_ordo = [[Asterids]] |ordo = [[Asterales]] |familia = [[Asteraceae]] |tribus = '''Heliantheae''' |tribus_authority = [[Alexandre de Cassini|Cassini]], 1819 |diversity = About 190 genera and 2500 species |diversity_link = Biodiversity |subdivision_ranks = Subtribes |subdivision = See text. |}} '''Heliantheae''' is the most well known [[Tribe (biology)|tribe]] of the [[sunflower]] family ([[Asteraceae]]). The name comes from the [[Ancient Greek|Greek]] word for ''sun flower''. The Heliantheae is the third largest tribe in the sunflower family, which has 190 [[genera]] and about 2500 [[species]]. Only the tribes [[Senecioneae]] and [[Astereae]] are larger. Most Heliantheae come from [[North America]] and [[South America]], and [[Mexico]]. A few genera come from tropical areas. Most Heliantheae are [[herb]]s or [[shrub]]s, but there are some that grow to the size of small trees. Leaves are usually [[trichome|hairy]] and arranged in opposite pairs. The [[anther]]s are usually black. == Uses == Heliantheae can be grown on farms. These include [[sunflower]]s and [[jerusalem artichoke]]s. Many garden flowers are also in this group, such as ''[[Coreopsis]]'', ''[[Cosmos (flower)|Cosmos]]'', ''[[Echinacea]]'', ''[[Rudbeckia]]'', and ''[[Zinnia]]''. There are also some [[weed]]s in the family. Species of ''Ambrosia'' ([[ragweed]]) produce lots of [[pollen]]. Each plant can produce about a billion grains of pollen over a season, and the plant is wind-[[pollinated]]. It is one of the main causes of [[hay fever]]. == Subtribes == In 1981 Harold Ernest Robinson came up with a new way to describe the tribe. He divided Heliantheae into 35 subtribes: * [[Ambrosiinae]] (includes: [[ragweed]]) * [[Baeriinae]] * [[Chaenactidinae]] * [[Clappiinae]] * [[Clibadiinae]] * [[Coreopsidinae]] (includes: ''[[Coreopsis]]'', ''[[Cosmos (flowe