Page:Memoir of a tour to northern Mexico.djvu/95

Rh name of O. clavata most appropriate. A singular plant, with the habit of a Ranunculus, but nearly related to Saururus, was also found in this neighborhood among grass on the banks of the Rio Grande. The genus has been described by Nuttall from specimens collected by him in California, but whether his Anemopsis californica is specifically identical with the new Mexican plant, remains to be seen, as this last has regularly 6 leaved involucres, about 6 stamens, and is perfectly glabrous.

While the last mentioned plants indicate that we approach another botanical region, we are surprised to meet here with Polygonum amphibium, common in the old and in the new world, and Cephalanthus Occidentalis, so widely diffused in the United States.

The famous desert, the Jornada del Muerto, furnished, as was to be expected, its quota of interesting plants. A Crucifera near Biscutella, of Europe, but with very short styles and white flowers, is here met with abundantly. I had considered it as the type of a new genus, when I found in Hooker's London Journal of Botany of February, 1845, Harvey's description of his new Californian genus Dithyrea, which probably must be made to embrace our plant as a second species.