26 ] The University of New Mexico 
• 
Where formerly cleared areas have gone back into the wild, 
the secondary vegetation has an apparently greater devel¬ 
opment of scrub than was originally the case. Throughout 
the district the native associations have been altered con¬ 
siderably, so that now there are large areas carrying an un¬ 
naturally large percentage of commercially worthless trees 
and shrubs. From these preliminary remarks it is evident 
that the present vegetation of Sinaloa cannot be considered 
“natural.” 
Generalizations as to dominant floristic categories, 
however, can be made with considerable accuracy. The 
Leguminoseae form the dominant order. The Mimosa , 
Senna (Caesalpinaceae) and bean (Fabaceae) families have 
probably more than a quarter of the total tree and shrub 
species of the area, and contribute possibly three-quarters 
of the individuals making up the vegetational landscape. 
Among the leading Mimosa genera are Proso'pis (mesquite) , 
Mimosa , Acacia (commonly known as husiaches), Callmn- 
clra, Enterolobium (huanacaxtle), Inga , and Pithecollobium 
(guamuchil, chino, una de gato, etc.). The Senna family 
includes such genera as Cassia (most of the species known 
as biches), Bauhinia, Haematoxylum (brasil), Caesalpinia 
(ebano, “dividivi,” palo Colorado, iguano, tabachin, etc.), 
Parkinsonio and Cercidium (palo verde). The numerous 
fabaceous genera include lndigofera (anil), Gliricidia, 
Parosela and Nissolia . These legumes, together with vari¬ 
ous cacti, chiefly columnar, dominate the inter-fluviatile 
areas and extend from hilltop to valley bottom. The “monte” 
thus formed is a dull green wilderness difficult to penetrate 
excepting along cut trails. 
In addition to the legumes, the river flood plains carry 
a considerable arboreal vegetation whose leading members 
represent a number of genera and families. The mulberry 
family contributes Chlorophora tinctoria (the mora, or fus¬ 
tic of commerce), nearly a dozen species of Ficus (higuera, 
nacapuli, matapalo, sabali, tescalama, etc.), and the Cas¬ 
tilla elastica (hule). The pine family is represented by the 
