The Hypopterygiaceae contains seven genera and 21 species, largely of the Southern Hemisphere but extending somewhat into the Northern Hemisphere; 2-3 genera and 2-3 species in the Neotropics.
Dendrohypopterygium arbuscula is found in southern temperate Argentina and Chile (also Juan Fernandez Islands) with three records from the tropical Andes (collections cited from Kruijer, 2002: “Peru: Cuming s.n. [BM, s. loc.]. - Lima Prov.: Hamilton 493, W of Lima. - Bolivia: La Paz: Pearie s.n. [BM], Yungas, Unduavi.”). Lopidium concinnum is found in eastern and southeastern Australia, New Zealand, temperate Chile (also Juan Fernandez Islands), southeastern Brazil, and a single record from Bolivia cited at 3350 m elevation (“La Paz: Pearie s.n. [BM]”) The name of the collector is Richard Pearce; that he made two collections in Bolivia of two separate taxa that are, at least in South America, found in temperate southern Chile and southeastern Brazil, seems questionable. The following key, from Kruijer (2002), is provided in the chance that one or both taxa may be found in the tropical Andes.
1. Plants pinnate to bipinnate; laminal cells collenchymatous, walls incrassate; costa of lateral frond percurrent or nearly so; setae mammillate … Lopidium concinnum
1. Plants usually palmate or umbellate, less often pinnate or flabellate; laminal cells prosenchymatous, walls thin; costa lateral frond leaves reaching 4/5 of leaf length; setae smooth … 2.
2. Stipe leaves obtuse, rounded, or truncate, usually appressed; frond leaves not bordered or with an interrupted border; ramification of frond pinnate to tetrapinnate … Dendrohypopterygium arbuscula
2. Stipe leaves acuminate, usually erect-patent to patent; frond leaves continuously bordered or mainly so; ramification of frond pinnate to bipinnate … Hypopterygium tamarisci
Hypopterygiaceae contiene siete géneros y 21 especies, principalmente del hemisferio Sur, pero extendiéndose algo en el hemisferio Norte; 2-3 géneros y 2-3 especies en el Neotrópico.