The relatively small area (around 16,870 km²) of Arica and Parinacota Region is located in the extreme north of Chile bordering the Department of Tacna in Peru. Much of the region is characterized by having a very low rainfall, especially in coastal areas where unlike other northern Chilean regions has little influence from the fog zone (lomas formations). The coastal hyper-arid belt runs from Arica (through Region Tarapacá) until the seaport of Antofagasta and as a result, there are exceptionally low levels of species diversity and plant density. The low number of endemics (79) is in part due to the aridity of much of this region but also because species share a common distribution between northern Chile and southern Peru and to a lesser extent with Bolivia. The Andean-fed river systems provide an important habitat for some endemic species, and the increase in rainfall at about 2800 m is sufficient to sustain a pre-altiplano shrub-steppe and at higher elevations the more species diverse pre-altiplano shrubland.
Endemic Taxa in Arica y Parinacota
- Adesmia atacamensis Phil.
- Aldama atacamensis (Phil.) E.E.Schill. & Panero
- Aloysia tarapacana (Botta) Lu-Irving & O’Leary
- Anatherostipa venusta (Phil.) Peñailillo
- Aphyllocladus denticulatus (J.Rémy) Cabrera var. calvus (Phil.) Cabrera
- Atriplex atacamensis Phil.
- Atriplex chizae Rosas
- Atriplex glaucescens Phil.
- Atriplex madariagae Phil.
- Balbisia microphylla (Phil.) Reiche
- Balbisia stitchkinii Ricardi
- Bowlesia paposana I.M. Johnst.
- Bromus gunckelii Matthei
- Calandrinia pilosiuscula DC
- Calceolaria stellariifolia Phil.
- Cardionema andinum (Phil.) A.Nelson & J.F.Macbr.
- Chuquiraga kuschelii Acevedo
- Cistanthe thyrsoidea (Reiche) Peralta & D.I. Ford
- Coreopsis suaveolens Sherff
- Cristaria viridiluteola Gay var. viridiluteola
- Cynodon nitidus Caro & E.A.Sánchez
- Dalea pennellii (J.F.Macbr.) J.F.Macbr. var. chilensis Barneby
- Eulychnia chorosensis P.Klaassen
- Eulychnia iquiquensis (K.Schum.) Britton & Rose
- Euphorbia tarapacana Phil.
- Fabiana ramulosa (Wedd.) Hunz. & Barboza
- Glandularia gynobasis (Wedd.) N. O’Leary & P. Peralta
- Hoffmannseggia aphylla (Phil.) G.P. Lewis & Sotuyo
- Huidobria fruticosa Phil
- Junellia bryoides (Phil.) Moldenke
- Lachemilla sandiensis (Pilg.) Rothm.
- Leucocoryne appendiculata Phil.
- Lupinus oreophilus Phil.
- Lupinus werdermannianus C.P.Sm.
- Metharme lanata Phil. ex Engl.
- Mirabilis acuta (Reiche) Heimerl
- Montiopsis parviflora (Phil.) D.I. Ford
- Myrosmodes nervosa (Kraenzl.) Novoa, C. Vargas & Cisternas
- Nassella pungens E.Desv.
- Neltuma flexuosa var. fruticosa (Meyen) C.E. Hughes & G.P. Lewis
- Neuontobotrys linearifolia (Kuntze) Al-Shehbaz
- Nolana rhombifolia Martic. & Quezada
- Nolana sedifolia Poepp.
- Nolana villosa (Phil.) I.M.Johnst.
- Nototriche auricoma (Phil.) A.W. Hill
- Nototriche nana A.W.Hill
- Oriastrum tarapacensis A.M.R.Davies
- Oxalis bulbocastanum Phil.
- Philippiamra amaranthoides (Phil.) Kuntze
- Plantago hispidula Ruiz & Pav.
- Portulaca philippii I.M.Johnst.
- Pseudognaphalium gayanum (J.Rémy) Anderb.
- Reyesia chilensis Gay
- Reyesia juniperoides (Werderm.) D'Arcy
- Senecio behnii Ricardi & Martic.
- Senecio ctenophyllus Phil.
- Senecio laucanus Ricardi & Martic.
- Senecio monttianus J.Rémy
- Senecio pappii Ricardi & Martic.
- Senecio pfisteri Ricardi & Martic.
- Senecio ricardii Martic. & Quezada
- Senecio zapahuirensis Martic. & Quezada
- Solanum brachyantherum Phil.
- Spergularia arbuscula (Gay) I.M.Johnst.
- Spergularia stenocarpa (Phil.) I.M.Johnst.
- Stellaria chilensis Pedersen
- Stevia philippiana Hieron.
- Tarasa pediculata Krapov.
- Tetragonia ovata Phil.
- Tiquilia atacamensis (Phil.) A.T.Richardson
- Trichocline caulescens Phil.
- Trisetum johnstonii (Louis‐Marie) Finot subsp. mattheii (Finot) Finot
- Villanova robusta Phil.
Endemic taxa only occurring in Arica y Parinacota
- Aloysia tarapacana (Botta) Lu-Irving & O’Leary
- Balbisia stitchkinii Ricardi
- Chuquiraga kuschelii Acevedo
- Lachemilla sandiensis (Pilg.) Rothm.
- Lupinus werdermannianus C.P.Sm.
- Nolana rhombifolia Martic. & Quezada
- Senecio laucanus Ricardi & Martic.
- Trisetum johnstonii (Louis‐Marie) Finot subsp. mattheii (Finot) Finot