This being a once in a lifetime year for wildflowers in southern Arizona, we will take this opportunity to document the wildflowers found within the boundaries (and perhaps a few in the area surrounding) the Casas Arroyo Homeowners Association in Sonoita, Arizona. The boundaries encompass approximately 210 acres through which Sonoita Creek flows, usually underground; a few drainages flowing into the creek are also present. The land can be described as rolling grasslands dotted with oaks. Not only is there the region surrounding the drainages containing both gravels and clay soils, but there are also hills composed mainly of coarse gravels. This range of conditions yields a broad range of vegetation, attracting a wide mix of birds and butterflies.

I should note here that many of the signature plants of the Sonoran desert are not found in this area, the altitude being too high and thus the minimum temperatures too cold. Among these are the Saguaro cactus, the creosote bush, brittle bush. You will find here plants that are at the high end of their range, such as the ocotillo, mixed with plants that are at the low end of their range, such as the oak trees. This provides an interesting mix of plants within a small area and several different habitats within the association.

The images have been taken with a digital camera, a Nikon Coolpix 900. This is convenient for moving the images directly to the computer. However there are also problems introduced using such a camera. All exposures are computed automatically; the focussing is done automatically. With subjects such as flowers, where the desired object may fill only a small part of the frame, it is sometimes difficult to obtain properly focussed and exposed images. Because the lens aperture is considerably smaller than with a standard 35mm camera, the lens cannot be stopped down to as small an f-ratio. This means that the depth of field that can be achieved is much smaller, giving difficulty when photographing very small flowers from a very close distance.

A disclaimer: I am not a botanist. I have never even taken a botany course. I am not using detailed guidebooks, but only the usual books available to amateurs. Some (many?) of the identifications may be close but not right on. Any help offered will certainly be appreciated. I will have trouble enough getting pictures, at the rate new flowers are appearing. I already have a group of unidentifed flowers and have put online a section of unidentified flowers for all to work on.