The species is quite common in areas with dry seasons, where it grows in dense colonies on periodically moist or wet clay, sandy clay, or sand, overlying limestone, dolomite, tuff or other calcareous rocks, basalt, lava, or volcanic rocks, or on soil in rock and wall crevices, often exposed, sometimes in partial shade, on banks along intermittent rivers, in grassland, open shrub vegetation, and open forests, also in towns and ruins, from 600 to 4420 m, but mostly >2000 m.Targionia hypophylla is defined here to include the morphologically similar and sympatric haploid and triploid cytotypes. The triploid was taxonomically separated from the haploid by Muller (1940), but as shown by Boisselier-Dubayle & Bischler (1999), the morphological characteristics of the 2 cytotypes (structure of epidermal pores, scales, spore size, and ornamentation) overlap, and their separation on morphological grounds is therefore precluded. The chromosome number of the Linnean type of T. hypophylla is unknown. When the cytotypes of the species would be given specific rank, lectotypification of T. hypophylla is not possible. Both cytotypes are probably present in the Neotropics, but chromosome counts are not yet available.Targionia hypophylla is easily distinguished in fertile condition by its bivalved, purplish black involucres at apex on ventral side of thallus, and by its small, discoid male branches.
Distribution and Ecology: The species is distributed throughout warm-temperate and tropical parts of the world. It has been recorded from Europe, up to S Scandinavia and Iceland in the North, the Mediterranean area, Macaronesia, Saharian, tropical and S Africa, Mascarenes, Ascension Is., Madagascar, SW and C Asia, Afghanistan, N India, Sri Lanka, Sikkim, Nepal, China, Tailand, Korea, Taiwan, Japan, Malaysia, Java, Oceania, New Zealand, Australia, and Tasmania. It is known from Canada, U.S.A. (Arizona, California, Colorado, Nevada, New Mexico, Oregon, Texas, Utah, Washington) in the New World, and in the Neotropics from Mexico (Guadalupe Is. (Sutliffe 1932), Baja California, Chiapas, D. F., Durango, Hidalgo, Mexico, Michoacán, Morelos, Oaxaca, Puebla, Querétaro, Tlaxcala, Veracruz), El Salvador (Haupt, 1942), Nicaragua, Costa Rica, Puerto Rico, Colombia (Meta, Magdalena (Winkler, 1976)), Ecuador (Chimborazo, Galápagos (Isabela)), Peru (Amazonas, An-cash, Apurimac, Arequipa, Cajamarca, Cuzco, Huancavelica (Buchloh, 1926), Huanuco, Junín (Stephani, 1916), La Libertad, Lima (Bryan, 1929)), Brazil (Goiás, Rio Grande do Sul (Vianna, 1976)), Bolivia (Chuquisaca, Cochabamba (Hassel de Menéndez, 1963), La Paz, Potosí, Tarija), Chile (Santiago, Valparaiso (Montagne, 1838)), Argentina (Buenos Aires, Catamarca, Cordoba (Hässel de Menéndez, 1963), Mendoza (Hässel de Menéndez, 1963), Neuquén, Rio Negro (Hässel de Menéndez, 1963), Salta (Hässel de Menéndez, 1963), Tucumán (Hässel de Menéndez, 1963)).