Rhipsalis trigona

Rhipsalis trigona Pfeiffer, Enum. Cact. 133. (1837)

Plant - stems stout, very much branched, 1.5 cm. in diameter, strongly 3-angled, the anglesor ribs alternating with those of adjoining joints;
Flowers - solitary, white to pinkish, widely spreading, sometimes 2 cm. broad;
Sepals - usually 3, short, obtuse;
Petals - generally 7, oblong, obtuse; filaments numerous, white;
Style - white; stigma-lobes 4, white;
Ovary - sunken in the branch;
Fruit - globose, 8 to 10 cm. in diameter, red
Type locality: Brazil.

DISTRIBUTION. Brazil (S Sao Paulo, Parana, E Santa Catarina): epiphyte in seasonal Atlantic forest, to c. 800 m altitude.

This name is neotypified here so as to maintain the usage established more than a century ago by Schumann (l.c.), Lindberg (l.c.) et al. and followed by nearly all later authors. It may be doubted, however, that Pfeiffer's plant was the same, since his description requires 'Areolae 2-4 lin. [c. 4-8 mm] distantes', which can scarcely apply to the plant we know today and suggests that he may have been describing a form of Lepismium cruciforme ('Num forsan Lepismii species?', Pfeiffer, l.c.). If the present solution is not acceptable (e.g. because it may be argued that the neotype is in serious conflict with the protologue), then the name will need to be conserved with a new type, or the species redescribed since there appears to be no other validly published name for it.

Glaziou (in Mem. Soc. bot. France 1(3): 327. (1909) reports R. trigona from Rio de Janeiro (Serra dos Orgaos) and Lombardi (1993: 73) expands its range further to include Espirito Santo. However, neither of these reports appear to be supported by specimens and on present knowledge the species does not appear to range further east than the region of the city of Sao Paulo.