Lagascea is a genus of flowering plants in the family Asteraceae.Cavanilles, Antonio José. 1802. Anales de Ciencias Naturales 6(18): 331–333 in SpanishCavanilles, Antonio José. 1802. Anales de Ciencias Naturales 6(18): plate 44 line drawing of Lagascea mollisTropicos, Lagascea Cav. It occurs primarily in Mexico, but some species extend into Central America and one reaches north into the western United States.Stuessy, T. F. 1978. Revision of Lagascea (Compositae, Heliantheae). Fieldiana, Botany 38: 75–133. One species, L. mollis, has been widely introduced to other localities around the tropics and subtropics.
Lagascea is a member of the same subtribe Helianthinae as the common sunflower, Helianthus annuus, but it looks different because it has heads that are reduced to have 1 (or 2) flowers, and are clustered into compound units that mimic heads and are sometimes called syncephalia.Harris, E. M. 1994. Developmental evidence for the derivation of syncephalia in Lagascea (Heliantheae; Asteraceae). American Journal of Botany 81: 1139–1148. The relationships of Lagascea are not well established, but the published work from molecular phylogenetic studies places it as the sister genus to Tithonia.Schilling, E. E. and J. L. Panero. 1996. Phylogenetic reticulation in subtribe Helianthinae. American Journal of Botany 83: 939-948. Two of the species are herbs, distinguished from each other by features of the heads, and the remaining species are shrubs and are distinguished primarily by vegetative features.
The genus is named after the Spanish botanist Mariano Lagasca (1776-1839).Genaust, Helmut (1976). Etymologisches Wörterbuch der botanischen Pflanzennamen
SpeciesThe Plant List search for LagasceaCONABIO. 2009. Catálogo taxonómico de especies de México. 1. In Capital Nat. México. CONABIO, Mexico City. Lagascea agustifolia D.C. - Guanajuato, Guerrero, Jalisco, México State, Morelos, Zacatecas, Nayarit, Sinaloa Lagascea aurea Stuessy - Michoacán Lagascea decipiens Hemsl. - Arizona (Pima + Santa Cruz Counties),Biota of North America Program 2013 county distribution map Mexico (from Sonora to Oaxaca) Lagascea helianthifolia H.B.K. - Mexico + Central America from Tamaulipas to Nicaragua Lagascea heteropappus Hemsl. - Guerrero, México State, Michoacán Lagascea mollis Cav. - Mexico + Central America Lagascea palmeri (B. Rob.) B. Rob. - Michoacán, Colima Lagascea rigida (Cav.) Stuessy - Guerrero, México State, Morelos, Puebla, Distrito Federal
References