Heliantheae
Encyclopedia
Heliantheae is the third largest tribe
in the sunflower
family (Asteraceae
). With some 190 genera and nearly 2500 recognized species, only the tribes Senecioneae
and Astereae
are larger. The name is derived from the genus Helianthus
, which is Greek
for sun flower. 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 shrub
s, 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.
The above statements about the size and distribution of the tribe apply to a broad definition of Heliantheae, which was followed throughout the 20th century. Some recent authors break the tribe up into a dozen or so smaller tribes.
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 weed
s. 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.
'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 stricto, 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. Such classifications may define a supertribe Helianthodae including these smaller tribes, the Eupatorieae, and a few other tribes such as Inuleae
.
In his 1981 revision of the Heliantheae, Harold Ernest Robinson divided the group into 35 subtribes:
See also: List of Asteraceae genera
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
in the sunflower
Sunflower
Sunflower is an annual plant native to the Americas. It possesses a large inflorescence . The sunflower got its name from its huge, fiery blooms, whose shape and image is often used to depict the sun. The sunflower has a rough, hairy stem, broad, coarsely toothed, rough leaves and circular heads...
family (Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
). With some 190 genera and nearly 2500 recognized species, only the tribes Senecioneae
Senecioneae
Senecioneae is the largest tribe of the Asteraceae, or the sunflower family, comprising approximately 150 genera and 3,000 species. Almost one-third of the species in this tribe are placed in the genus Senecio...
and Astereae
Astereae
Astereae is a tribe of plants in the family Asteraceae that includes annuals, biennials, perennials, subshrubs, shrubs and trees. Plants within the tribe are present nearly worldwide divided into 170 genera and more than 2,800 species...
are larger. The name is derived from the genus Helianthus
Helianthus
Helianthus L. is a genus of plants comprising 52 species in the Asteraceae family, all of which are native to North America, with some species Helianthus L. is a genus of plants comprising 52 species in the Asteraceae family, all of which are native to North America, with some species Helianthus...
, which is Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
for sun flower. Most genera and species are found in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, particularly in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. A few genera are pantropical.
Most Heliantheae are herbs or shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, but there are some that grow to the size of small trees. Leaves are usually hairy
Trichome
Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
and arranged in opposite pairs. The anthers are usually blackened.
The above statements about the size and distribution of the tribe apply to a broad definition of Heliantheae, which was followed throughout the 20th century. Some recent authors break the tribe up into a dozen or so smaller tribes.
Uses
Commercially important plants in the Heliantheae include sunflowerSunflower
Sunflower is an annual plant native to the Americas. It possesses a large inflorescence . The sunflower got its name from its huge, fiery blooms, whose shape and image is often used to depict the sun. The sunflower has a rough, hairy stem, broad, coarsely toothed, rough leaves and circular heads...
and jerusalem artichoke
Jerusalem artichoke
The Jerusalem artichoke , also called the sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from Eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas...
. Many garden flowers are also in this group, such as Coreopsis, Cosmos
Cosmos (flower)
Cosmos is a genus, with the same common name of Cosmos, of about 20–26 species of annual and perennial plants in the family Asteraceae.-Range:...
, Echinacea
Echinacea
Echinacea is a genus of herbaceous flowering plants in the daisy family, Asteraceae. The nine species it contains are commonly called purple coneflowers. They are endemic to eastern and central North America, where they are found growing in moist to dry prairies and open wooded areas. They have...
, Rudbeckia
Rudbeckia
Rudbeckia is a plant genus of 23 species in the family Asteraceae. The species are commonly called coneflowers and black-eyed-susans; all are native to North America and many species are cultivated in gardens for their showy yellow or gold flower heads.The species are herbaceous, mostly perennial...
, and Zinnia
Zinnia
Zinnia is a genus of 20 species of annual and perennial plants of family Asteraceae, originally from scrub and dry grassland in an area stretching from the American Southwest to South America, but primarily Mexico, and notable for their solitary long-stemmed flowers that come in a variety of bright...
.
In addition to the benefits brought by the group, there are also problematic weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s. Species of Ambrosia (ragweed
Ragweed
Ragweeds are flowering plants in the genus Ambrosia in the sunflower family Asteraceae. Common names include bitterweeds and bloodweeds....
) produce large quantities of pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
. 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
Allergen
An allergen is any substance that can cause an allergy. In technical terms, an allergen is a non-parasitic antigen capable of stimulating a type-I hypersensitivity reaction in atopic individuals....
of all pollens, and the prime cause of hayfever.
Subtribes and representative genera
The traditional circumscription of the Heliantheae arises from CassiniAlexandre de Cassini
Count Alexandre Henri Gabriel de Cassini was a French botanist and naturalist, who specialised in the sunflower family ....
'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 stricto, Madieae, Millereae, Perityleae, Polymnieae, and Tageteae
Tageteae
Tageteae is a tribe of the plant family Asteraceae. It consists of approximately 216 species divided among 28 genera. All are found in the New World, with a center of diversity in the Mexican highlands. The type genus is Tagetes ....
. Because the Eupatorieae
Eupatorieae
Eupatorieae is a tribe of over 2000 species of plants in the aster family. Most of the species are native to tropical, subtropical, and warm temperate areas of the Americas, but some are found elsewhere...
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. Such classifications may define a supertribe Helianthodae including these smaller tribes, the Eupatorieae, and a few other tribes such as Inuleae
Inuleae
Inuleae is a tribe of flowering plants in the subfamily Asteroideae.-Genera:This tribe includes the following genera:...
.
In his 1981 revision of the Heliantheae, Harold Ernest Robinson divided the group into 35 subtribes:
- Ambrosiinae (includes: ragweedRagweedRagweeds are flowering plants in the genus Ambrosia in the sunflower family Asteraceae. Common names include bitterweeds and bloodweeds....
) - Baeriinae
- Chaenactidinae
- Clappiinae
- Clibadiinae
- Coreopsidinae (includes: Coreopsis, CosmosCosmos (flower)Cosmos is a genus, with the same common name of Cosmos, of about 20–26 species of annual and perennial plants in the family Asteraceae.-Range:...
) - Coulterellinae
- Desmanthodiinae
- Dimeresiinae
- Ecliptinae
- Engelmanniinae (includes: rosinweedRosinweedSilphium is a genus of about 20 species of flowering plants in the family Asteraceae, native to eastern North America. Members of the genus, commonly known as Rosinweeds, are herbaceous perennial plants growing to 0.5-4 m tall, with yellow flowerheads...
) - Enhydrinae
- Espeletiinae
- Fitchiinae
- Flaveriinae
- Gaillardiinae
- Galinsoginae (includes: Hidalgoa)
- Guardiolinae
- Helianthinae (includes: sunflowerSunflowerSunflower is an annual plant native to the Americas. It possesses a large inflorescence . The sunflower got its name from its huge, fiery blooms, whose shape and image is often used to depict the sun. The sunflower has a rough, hairy stem, broad, coarsely toothed, rough leaves and circular heads...
s) - Heptanthinae
- Hymenopappinae
- Jaumeinae
- Lycapsinae
- Madiinae (includes: tarweeds, Hawaiian silverswordSilversword allianceSilversword alliance refers to an adaptive radiation of over 50 species in the composite or sunflower family, Asteraceae. The group is endemic to Hawaii, and is derived from a single immigrant to the islands...
s) - Marshalliinae
- Melampodiinae
- Milleriinae
- Montanoinae
- Neurolaeninae
- Pectidinae
- Peritylinae
- Pinillosinae
- Polymniinae
- Rudbeckiinae (includes: EchinaceaEchinaceaEchinacea is a genus of herbaceous flowering plants in the daisy family, Asteraceae. The nine species it contains are commonly called purple coneflowers. They are endemic to eastern and central North America, where they are found growing in moist to dry prairies and open wooded areas. They have...
, RudbeckiaRudbeckiaRudbeckia is a plant genus of 23 species in the family Asteraceae. The species are commonly called coneflowers and black-eyed-susans; all are native to North America and many species are cultivated in gardens for their showy yellow or gold flower heads.The species are herbaceous, mostly perennial...
) - Varillinae
- Zaluzaniinae
- Zinniinae (includes: ZinniaZinniaZinnia is a genus of 20 species of annual and perennial plants of family Asteraceae, originally from scrub and dry grassland in an area stretching from the American Southwest to South America, but primarily Mexico, and notable for their solitary long-stemmed flowers that come in a variety of bright...
)
See also: List of Asteraceae genera