Question: To which continent are Aira and Dimorphotheca both native?

Context articles: Aira caryophyllea
Aira
Military history of North America
Dimorphotheca
Aira praecox
African art
Dimorphotheca ecklonis
Women in Latin music
Dimorphotheca sinuata
Dimorphotheca cuneata

Aira caryophyllea is a species of grass known by the common name silver hairgrass.
 This is a species of bunchgrass which is native to Europe.
Aira is a genus of Old World plants in the grass family, native to western and southern Europe, central and southwest Asia, plus Africa.
The Military history of North America can be viewed as having four distinct phases.
 The first is the precolonial period, during which warfare and conquest occurred from time to time between Native American tribes and alliances.
 The second is the colonial period following the European discovery of the continent, during which the region saw both European efforts to wrest territories from their native inhabitante, and where European nations used their North American colonial possessions to wage wars with one another for the control of resources.
 This phase culminated in the American Revolution, with the continent thereafter shifting away from European military domination.
 The third phase was one of internal discord on the continent, including skirmishes between the United States and Canada, the Mexican–American War, the American Civil War and similar internal violence in Mexico, the Indian Wars, and the expulsion of the last major colonial bastion in the Spanish–American War.
Dimorphotheca is a genus of plants in the sunflower family, native to Africa and Australia.
 is one of eight genera of the Calenduleae, with a centre of diversity in Southern Africa.
 Some species can hybridize with "Osteospermum", and crosses are sold as cultivated ornamentals.
 The name ""Dimorphotheca"" comes from the Greek "Dis" "Morphe" and "Theka", meaning "two shaped fruit", referring to the dimorphic cypselae, a trait inherent to members of the Calenduleae.
 Plants of this genus usually have bisexual flowers.
Aira praecox is a species of grass known by several common names, including early hair-grass, yellow hairgrass and spike hairgrass.
 It is native to Europe.
 It also grows in North America as an introduced species, where it can be found on the east and west coasts in sandy or rocky areas, such as beaches and roadsides.
 This is a tuft-forming annual grass growing up to about 25 centimeters in maximum height.
 The thin, narrow leaves are located at the base of the stem.
 It bears very small inflorescences of purple-tinted green bisexual spikelets.
African art describes the modern and historical paintings, sculptures, installations, and other visual culture from native or indigenous Africans and the African continent.
 The definition may also include the art of the native African, African diasporas, such as African American, Caribbean and other American art.
 Despite this diversity, there are some unifying artistic themes when considering the totality of the visual culture from the continent of Africa.
Dimorphotheca ecklonis or Osteospermum, (Cape marguerite, Van Staden's river daisy, Sundays river daisy, white daisy bush, blue-and-white daisy bush, star of the veldt) is an ornamental plant.
 A native plant of South Africa, this plant is now regarded as a weed in parts of Australia, particularly Victoria and Western Australia.
Women have made significant contributions to Latin music, a genre which predates Italian explorer Christopher Columbus' arrival in Latin America in 1492 and the Spanish colonization of the Americas.
 The earliest musicians were Native Americans, hundreds of ethnic groups across the continent, whose lyrics "reflect conflict, beauty, pain, and loss that mark all human experience."
 Indigenous communities reserved music for women, who were given equal opportunities with men to teach, perform, sing, and dance.
 Ethnomusicologists have measured ceramic, animal-bone, and cane flutes from the Inca Empire which indicate a preference for women with a high vocal range.
 Women had equal social status, were trained, and received the same opportunities in music as men in indigenous communities until the arrival of Columbus in the late 15th century.
 European settlers brought patriarchal, machismo ideologies to the continent, replacing the idea of equality between men and women.
 They equated native music with "savagery" and European music with "civilization".
 Female musicians tended to be darker-skinned as a result of the slave trade (which increased the population of African slaves), and contemporary society denigrated music as a profession.
 Latin music became Africanized, with syncopated rhythms and call-and-response; European settlement introduced harmony and the Spanish décima song form.
Dimorphotheca sinuata, the glandular Cape marigold, Namaqualand daisy, or orange Namaqualand daisy; syn.
 "Dimorphotheca aurantiaca" hort.)
 is an African species of plants native to southern Africa.
 It is also widely cultivated as an ornamental and naturalized in parts of the United States, primarily California and Arizona.
Dimorphotheca cuneata , commonly known as the rain flower or white bietou, is a plant species native to South Africa (Fynbos, Succulent Karoo, Nama Karoo, etc.).
 It is also widely grown as an ornamental and reportedly sparingly naturalized in Gila County in the US State of Arizona.