Taxonomic revision of Zamia in Mega-Mexico

Abstract

The genus Zamia is revised for Mega-Mexico, with 22 species recognized and described. The study presents a taxonomic clarification for the genus in Mesoamerica, a contribution that provides the foundation for a future monograph for Zamia in the Neotropics. The largest proportion of species richness and endemism for the genus is concentrated in southeastern Mexico, among the states of Chiapas, Oaxaca, Tabasco, and Veracruz, an area that is considered highly diverse in floristic terms. Distribution maps and a key to species are also provided, as well as complete descriptions of the specimens examined, including information on nomenclatural types, habitats, synonymies, and etymologies. A lectotype is designated for Zamia loddigesii, and neotypes for Z. galeottii, Z. leiboldii var. angustifolia, and Z. variegata. Zamia spartea is illustrated for the first time, and chromosome numbers for Z. herrerae are reported and illustrated. Finally, scanning electron micrographs of leaflet trichome character states are presented, along with a discussion of their systematic implications within the group.

Disentangling the identity of Zamia from Mexican Pacific seaboard, with a description of a new species

“…These taxonomic groups with morphological foliar affinity have disjunct distribution patterns and their taxonomic identification is preferentially based on the examination of reproductive characters (cf. Nicolalde-Morejón et al 2009). The variation in the shape and length of leaves and leaflets among populations of the aforementioned group of species turns them into highly polymorphic taxa.…”

“…Moretti & Vázq. Torres, have been modified by morphological variation throughout their range (cf. Stevenson et al 1998, Calonje and Meerman 2009, Nicolalde-Morejón et al 2009). Another example is Z. paucijuga, which was published at the beginning of the 20th century (Wieland 1916) but not widely collected until the last three decade.…”

“…Z. paucijuga shows high leaf and leaflet morphological variation; however, taxonomically it has remained stable in contrast to the taxonomic-nomenclatural history of Z. loddigesii. The latter species has less morphological variation in leaves, but it has various nomenclatural entities attached to it (as much as 12 names cataloged as synonyms; see Nicolalde-Morejón et al 2009).…”

“…Zamia paucijuga exhibits more than threefold greater degree of population variation than other taxa in Mexico (cf. Nicolalde-Morejón et al 2009). Unexpectedly, during review of herbarium specimens and fieldwork associated with a long-term research projects on Mexican Zamiaceae, a new species from the coastal plain of the State of Michoacán, Mexico, was discovered.…”

“…An opposite case to Zamia paucijuga is the micro-endemic Zamia species, such as Z. spartea A. DC., which occurs in a small area of tropical deciduous forests on the Isthmus of Tehuantepec (Oaxaca, Mexico;Nicolalde-Morejón et al 2009). This species is somewhat similar to the extreme and distinct narrow leaflet form of Z. paucijuga, described here as new.…”