Oreopolus Schltdl. (Rubiaceae: Coussareae) Charlotte M. Taylor [webpage] Missouri Botanical Garden P.O. Box 299 St. Louis, MO 63166 Oreopolus glacialis, from Ricardi (1963) Oreopolus Schltdl. includes one South American species of rather succulent, hemicryptophytic shrubs with well developed rootstocks. Oreopolus glacialis (Poepp. & Endl.) Ricardi is found in the southern Andes from central Chile and Argentina south to Tierra del Fuego. It can be recognized by its ternate leaves, its triangular stipules that are interpetiolar and fused to the petiole bases on each side, its flowers that are solitary or few in terminal and axillary clusters, its yellow salverform corollas with slender long tubes, and its papery loculicidal capsules. The flowers are diurnal and distylous. The tissues do contain raphides, although these may be difficult to observe. Oreopolus has been confused with another genus of southern South America, Cruckshanksia Hook. & Arn. However these genera differ in several characters, as summarized in the key below. Oreopolus and its relationship to Cruckshanksia have been studied by Ricardi (1963) and Taylor (1996), and Oreopolus has been treated floristically recently by Moore (1983) and Bacigalupo (1999). Oreopolus was previously included in the Hedyotideae by many authors, although Bremekamp and later Anderson & Rova (1999) placed it in the Cruckshanksieae. More recently, based on molecular data Bremer & Manen (2000) transferred both Oreopolus and Cruckshanksia to the neotropical tribe Coussareae. In their expanded circumscription Coussareae comprises a notable range of fruit types, from single- to multi-seeded, fleshy, indehiscent fruits (Coussarea, Coccocypselum) to leathery schizocarps (Declieuxia) and dry multi-seeded capsules (Heterophyllaea); it is not yet clear what morphological features unite the genera now placed in this tribe. Key to Oreopolus and Cruckshanksia 1. Leaves opposite or occasionally subalternate; stipules triangular to bilobed or erose, usually separated along the stems due to good development of the internodes that separate the leaves; calyx lobes not enlarged or often one or several of them prolonged into white or colored, petaloid appendages (i.e., calycophylls); capsules dehiscent from the base into 2-5 valves...Cruckshanksia 1. Leaves ternate or occasionally opposite; stipules triangular and usually imbricated due to the limited development of the internodes, so the leaves are hardly separated; calyx lobes never enlarged into petaloid appendages; capsules dehiscent from the apex into 2 valves...Oreopolus References Andersson, L. & J.H.E. Rova. 1999. The rps16 intron and the phylogeny of the Ruboideae (Rubiaceae). Pl. Syst. Evol. 214: 161-186. Bacigalupo, N.M. 1999. Rubiaceae. In: M. N. Correa, Flora Patagonica Parte 6: 423-443. Bremer, B. & J.-F. Manen. 2000. Phylogeny and classification of the subfamily Rubioideae (Rubiaceae). Pl. Syst. Evol. 225: 43-72. Moore, D.M. 1983. Flora of Tierra del Fuego. Ricardi, M. 1963. Rehabilitación del género Oreopolus Schlecht. Gayana, Bot. 7: 3-7. Taylor, C.M. 1996. Taxonomic revision of Cruckshanksia and Oreopolus (Rubiaceae: Hedyotideae). Ann. Missouri Bot. Gard. 83: 461-479. TOP List of Names and Synonyms of Oreopolus Accepted names are presented in bold; synonymous names appear with an equals sign. Further information on these names can be found in the TROPICOS database [http://www.tropicos.org/]. Cruckshanksia glacialis Poepp. & Endl. = Oreopolus glacialis Oreopolus citrinus Shldtl. = Oreopolus glacialis Oreopolus glacialis (Poepp. & Endl.) Ricardi, central Chile and Argentina to Tierra del Fuego Oreopolus glacialis var. pilosus Ricardi = Oreopolus glacialis Oreopolus macrantha (Phil.) Ricardi = Cruckshanksia macrantha Oreopolus palmae (Clos) Ricardi = Cruckshanksia palmae Oreopolus patagonicus Speg. = Oreopolus glacialis Text and Images, unless otherwise indicated, Copyright © by Charlotte M. Taylor. All rights reserved. This page was revised on April 8, 2008. TOP