Heliantheae

Taxobox
name = Heliantheae

---

image_width = 240px
image_caption = Sunflowers display bright yellow colors.
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Asterales
familia = Asteraceae
tribus = Heliantheae
tribus_authority = Cassini, 1819
diversity = About 190 genera and 2500 species
diversity_link = Biodiversity
subdivision_ranks = Subtribes
subdivision = See text.

The tribe Heliantheae is the most familiar tribe of the sunflower family (Asteraceae). The name is derived from the genus "Helianthus", which is Greek for "sun flower". The Heliantheae is the third largest tribe in the sunflower family, with some 190 genera and nearly 2500 recognized species. Only the tribes Senecioneae and Astereae are larger. Most genera and species are found in North America and South America, particularly in Mexico. A few genera are pantropical.

Most Heliantheae are herbs or shrubs, but there are some that grow to the size of small trees. Leaves are usually hairy and arranged in opposite pairs. The anthers are usually blackened.

Uses

Commercially important plants in the Heliantheae include sunflower and jerusalem artichoke. Many garden flowers are also in this group, such as "Coreopsis", "Cosmos", "Echinacea", "Rudbeckia", and "Zinnia".

In addition to the benefits brought by the group, there are also problematic weeds. Species of "Ambrosia" (ragweed) produce large quantities of pollen. Each plant is reputed to be able to produce about a billion grains of pollen over a season, and the plant is wind-pollinated. It is highly allergenic, as the greatest pollen allergen of all pollens, and the prime cause of hayfever.

ubtribes and representative genera

The traditional circumscription of the Heliantheae arises from Cassini's 19th century classification of the Asteraceae. This broad Heliantheae has been divided by some authors into smaller tribes: Bahieae, Chaenactideae, Coreopsideae, Helenieae, Heliantheae sensu stricta, Madieae, Millereae, Perityleae, Polymnieae, and Tageteae. Because the Eupatorieae originated from within the Heliantheae (broadly defined), to maintain monophyletic taxa it is necessary to either make Eupatorieae a subtribe within Heliantheae or to split the Heliantheae into smaller tribes.cite web | url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=20539 | title = 187n. Asteraceae tribe Eupatorieae | work = Flora of North America (Vol. 21 Page 456, 459) | accessdate = 2007-10-06 ] cite web | url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=10074 | work = Flora of North America | title = 187. Asteraceae | accessdate = 2007-12-07]

In his 1981 revision of the Heliantheae, Harold Ernest Robinson divided the group into 35 subtribes:

* Ambrosiinae (includes: ragweed)
* Baeriinae
* Chaenactidinae
* Clappiinae
* Clibadiinae
* Coreopsidinae (includes: "Coreopsis", "Cosmos")
* Coulterellinae
* Desmanthodiinae
* Dimeresiinae
* Ecliptinae
* Engelmanniinae (includes: rosinweed)
* Enhydrinae
* Espeletiinae
* Fitchiinae
* Flaveriinae
* Gaillardiinae
* Galinsoginae (includes: "Hidalgoa")
* Guardiolinae
* Helianthinae (includes: sunflowers)
* Heptanthinae
* Hymenopappinae
* Jaumeinae
* Lycapsinae
* Madiinae (includes: tarweeds, Hawaiian silverswords)
* Marshalliinae
* Melampodiinae
* Milleriinae
* Montanoinae
* Neurolaeninae
* Pectidinae
* Peritylinae
* Pinillosinae
* Polymniinae
* Rudbeckiinae (includes: "Echinacea", "Rudbeckia")
* Varillinae
* Zaluzaniinae
* Zinniinae (includes: "Zinnia")

"See also: List of Asteraceae genera"

References

* Bremer, Kåre. (1994). "Asteraceae: Cladistics & Classification". Portland, OR: Timber Press. ISBN 0-88192-275-7.
* Robinson, Harold Ernest. (1981). "A Revision of the Tribal and Subtribal Limits of the Heliantheae (Asteraceae)". "Smithsonian Contributions to Botany": 51.
* Strother, John L. (1991). "Taxonomy of Complaya, Elaphandra, Iogeton, Jefea, Wamalchitamia, Wedelia, Zexmenia, and Zyzyxia (Compositae - Heliantheae - Ecliptinae)". "Systematic Botany Monographs": 33. ISBN 0-912861-33-9.

External links

*cite journal
last =Cassini
first =Alexandre de
authorlink =Alexandre de Cassini
title = unknown
journal =Journal de Physique, de Chimie et d'Histoire Naturelle
volume = 88
pages =196
location =Paris
date =1794-1823
url =http://www.archive.org/details/journaldephysiqu88pari
id =J. Phys. Chim. Hist. Nat. Arts
accessdate = 2008-06-30