Coreopsis () is a genus of flowering plants in the family Asteraceae. Common names include calliopsis and tickseed, a name shared with various other plants.
Description
These plants range from in height. The flowers are usually yellow with a toothed tip, but may also be yellow-and-red bicolor. They have showy flower heads with involucral bracts in two distinct series of eight each, the outer being commonly connate at the base. The flat fruits are small and dry and look like insects.
There are 75–80 species of Coreopsis, all of which are native to North, Central, and South America. The name Coreopsis is derived from the Ancient Greek words (), meaning "bedbug", and (), meaning "view", referring to the shape of the achene.
Taxonomy
Coreopsis is a variable genus closely related to Bidens. In fact, neither Coreopsis nor Bidens, as defined in the 20th century, is strictly monophyletic. Coreopsis is best described as paraphyletic. Previously (1936), Coreopsis was classified into 11 sections and 114 species, but the African species were subsequently reclassified as Bidens, leaving the North and South American species, some 75–80 in all, under Coreopsis. 45 species are in the 11 North American sections, and the remaining 35 are in the South American section Pseudoagarista. The North American species fall into two broad groups, with 5 sections and 12 species in Mexico and North America and the remaining 5 sections and 26 species in Eastern North America.
One group which does seem to be monophyletic consists of temperate species from North America, including five sections of Coreopsis, Bidens coronata and Bidens tripartita, and the genus Thelesperma (five species).
Classification
Sections
One classification (GRIN) of the genus consists of eleven sections, shown by cladistic relationships with number of species in parentheses.
Coreopsis sect. Pseudoagarista (35)
Selected species
See:
Section Anathysana
Coreopsis cyclocarpa S.F.Blake
Section Calliopsis
Coreopsis bicolor
Coreopsis leavenworthii Torr. & A.Gray – Leavenworth's tickseed
Coreopsis paludosa M.E.Jones
Coreopsis tinctoria Nutt. – plains coreopsis
Section Coreopsis
Coreopsis auriculata L. – lobed tickseed
Coreopsis bakeri E.E.Schill. Coreopsis basalis (A.Dietr.) S.F.Blake – goldenmane tickseed Coreopsis grandiflora Hogg ex Sweet – large-flowered tickseed Coreopsis intermedia Sherff – goldenwave tickseed Coreopsis lanceolata L. – lance coreopsis, lance-leaf tickseed Coreopsis nuecensis A.Heller – crown tickseed Coreopsis nuecensoides E.B.Sm. – Rio Grande tickseed Coreopsis pubescens Elliott – star tickseed Coreopsis wrightii (A.Gray) H.M.Parker – rock tickseed
Section Electra
Coreopsis cuneifolia Greenm. Coreopsis mexicana Coreopsis mutica DC.
Section Eublepharis
Coreopsis floridana E.B.Sm. – Florida tickseed
Coreopsis gladiata Walter – coastalplain tickseed
Coreopsis integrifolia Poir. – fringeleaf tickseed
Coreopsis linifolia Nutt. – Texas tickseed
Coreopsis nudata Nutt. – Georgia tickseed
Coreopsis rosea Nutt. – pink tickseed
Section Gyrophyllum (syn. Palmatae) Coreopsis delphiniifolia Lam. – larkspurleaf tickseed Coreopsis major Walter – greater tickseed Coreopsis palmata Nutt. – stiff tickseed Coreopsis pulchra F.E.Boynton – woodland tickseed Coreopsis tripteris L. – tall tickseed Coreopsis verticillata L. – whorled tickseed
Section Leptosyne
Coreopsis douglasii (DC.) H.M.Hall – Douglas's tickseed
Coreopsis californica (Nutt.) H.Sharsm. – California tickseed
Coreopsis stillmanii (A.Gray) S.F.Blake – Stillman's tickseed
Section Pseudoagarista
South America, 35 species
Coreopsis mcvaughii D.J.Crawford
Coreopsis petrophila A.Gray
Coreopsis petrophiloides B.L.Rob. & Greenm. Coreopsis rudis (Benth.) Hemsl.
Section Pugiopappus
Coreopsis bigelovii (A.Gray) Voss – Bigelow's tickseed
Coreopsis calliopsidea (DC.) A.Gray – leafstem tickseed
Coreopsis hamiltonii (Elmer) H. Sharsm. – Mount Hamilton tickseed
Section Silphidium
Coreopsis latifolia Michx. – broadleaf tickseed
Section Tuckermannia
Coreopsis gigantea (Kellogg) H.M.Hall – giant coreopsis
Coreopsis maritima (Nutt.) Hook.f. – sea dahlia
Formerly placed here
Distribution and habitat
North American Coreopsis can be found in two habitats in the wild, growing along roadsides and open fields throughout the Eastern United States and Canada. In this environment the plant will self-sow.