notes This enchanted area is rich in interesting denizens of the regional flora of the Central Desert of Baja California Norte. A number of distinctive & characteristic taxa are visible here...and, remarkably, many occur as pairs of species from genera and/or morphological plant-types associated with this arid habitat. In particular, there are: • Two types of large, columnar, stem-succulent cacti:
Cardón (Pachycereus pringlei); and Senita (Pachycereus schottii, syn. Lophocereus schottii);
• Two pairs of sarco-caulescent taxa:
Two members of the (currently monogeneric) family Fouquieriaceae: the Boojum Tree or Cirio (Fouquieria columnaris...formerly Idria columnaris); and Ocotillo (Fouquieria splendens);
Two species of so-called 'elephant tree': Bursera microphylla and Pachychormus discolor...whose trunks & branches are swollen with water-storage tissue, and whose bark peels off to allow the photosynthetic trunks & stems to receive light for producing carbohydrate during most the year when they remain nearly leafless;
• There are also members of two genera of native palm tree:
The Mexican Blue Palm (Brahea armata); and either one or both of: the Mexican Fan Palm (Washingtonia robusta), and the California Fan Palm (Washingtonia filifera).
Note that the Flora of North America treatment separates the Washingtonia species by trunk diameter (robusta diam. < 80 cm; filafera diam. > 100 cm); while A. Henderson's 1995 'Field guide to the Palms of the Americas' gives additional characters, but they seem rather ambiguous and overlap. And while the 1987 paper by J. W. Cornett titled 'Three palm species at Cataviña'(Principes 31: 12–13...which I can't find online) stated that both W. robusta and W. filifera occur in the Cataviña area; that seems contradicted by this 2011 paper by Minnich et. al., which indicates that the southern end of the range of W. filafera is in the Sierra Juarez (far to the north or Cataviña)—and they opine that the species in the Cataviña area is W. robusta. Various references indicate the the distinctions between the two Washingtonia species are ambiguous and need further study. At present I'm not able to resolve the question of whether only W. robusta, or both it and W. filifera occur here (if they are indeed different).
The 1990 paper 'Water relations of stem succulent trees in north-central Baja California' focuses on the 'sarco-caulescent' boojum & elephant trees and was based on field research done in the Cataviña area. Many other interesting plant taxa are present in the area.
