4. Talinum
Adans.
About 15
species, southern U.S. to South America, Africa.
In recent
decades, phylogenetic studies have supported the segregation of the New World Phemeranthus
from the mainly African genus Talinum (Carolin, 1987; Hershkovitz, 1993;
Hershkovitz and Zimmer, 1997; Applequist and Wallace, 2001; Edwards et al.,
2005; Nyffeler, 2007). In fact, the two groups are not closely related within
the family. Most species of Phemeranthus have elongate, tubular leaves,
as opposed to the relatively broad, flattened leaf blades in Talinum in
the strict sense. There are also differences in the morphology of the capsule
wall, seed coat, and pollen. Species of Phemeranthus also have the seeds
covered with a thin membrane at maturity, which is lacking in Talinum.