A New Species of Parodia (Cactaceae, Notocacteae) from Rio Grande do Sul, Brazil Marlon C. Machado and Reto Nyffeler Institut fu¨r Systematische Botanik, Universita¨tZu¨rich, Zollikerstrasse 107, CH-8008 Zu¨rich, Switzerland.
[email protected] Urs Eggli Sukkulenten-Sammlung Zu¨rich, Mythenquai 88, CH-8002 Zu¨rich, Switzerland.
[email protected] Joa˜o F. Larocca e Silva Universidade do Vale do Rio dos Sinos (Unisinos), Av. Unisinos 950, Bairro Cristo Rei, 93022-000, Sa˜o Leopoldo, Rio Grande do Sul, Brazil.
[email protected] ABSTRACT . A new species, Parodia gaucha M. son, 2001) distributed through the eastern part of Machado & Larocca (Cactaceae, Notocacteae), from central South America. The species occur in two Encruzilhada do Sul, Rio Grande do Sul, Brazil, is centers of diversity (Buxbaum, 1964, 1966–1967, described and illustrated. The new species is 1967a, b, 1975; Endler & Buxbaum, 1974): (1) the morphologically very similar to P. muricata (Otto ex lowland pampas regions of southern Brazil (particu- Pfeiffer) Hofacker but can be distinguished from the larly in the state of Rio Grande do Sul), Uruguay, latter by the presence of a conical projection below eastern Paraguay, and northeastern Argentina; and (2) each areole, the higher number of shallower and on the eastern slopes of the Andes in northwestern narrower ribs, more closely spaced areoles, higher Argentina and eastern Bolivia. Many species have number of spines, different color of the spines, and limited distribution ranges and are often threatened by seeds with minutely striate testa-cell surfaces. grazing, agriculture, and habitat modification. The stems of Parodia generally have tuberculate RESUMO .