This prickly pear on Lasky Mesa appears to have many of the characteristics of the Engelmann prickly-pear, Opuntia engelmannii, but is more likely a cross involving O. engelmannii. One such cross is O. littoralis X (O. engelmannii X O. phaeacantha ) which is referred to as O. ×occidentalis in the Jepson Manual. Here's a closer view of the stamens and pistil.

From a run in in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch) on May 23, 2007.

Blue oak (Quercus douglasii) is a characteristic oak of the lower elevations of the Sierra foothills and coastal mountains, its range essentially encircling California's Central Valley.

Based on its reported range, Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch) contains one of the southernmost populations of blue oak within its range. However, the predominate deciduous oak in the area is valley oak (Quercus lobata), and occurrences of blue oak appear to be rare. Regional climate modeling suggests that over the next century the range of blue oak could shift northward and diminish to nearly 60% of its current range.

Blue oak is reported to hybridize with valley oak, however a 2005 study suggests hybrids of these species may be more rare than generally accepted.

The photograph of the leaves of a blue oak was taken on a run along East Las Virgenes Canyon to Lasky Mesa on April 24, 2007. A valley oak immediately adjacent to this blue oak was killed in the 2005 Topanga Fire.

Related posts: Valley Oak Savannah, Laskey Mesa Oak

Technical papers:

Modeled regional climate change and California endemic oak ranges.
Kueppers, L.M., M.A. Snyder, L.C. Sloan, E.S. Zavaleta, and Brian Fulfrost. 2005. 
Proceedings of the National Academy of Sciences of the United States of America, 102(45): 16281 – 16286.

Limited hybridization between Quercus lobata and Quercus douglasii (Fagaceae) in a mixed stand in central coastal California.
Kathleen J. Craft, Mary V. Ashley and Walter D. Koenig.
American Journal of Botany. 2002;89:1792-1798.

As evidenced by their survival, native plants are generally well adapted to the environment in which they live. Fire, flood, drought, heat or cold, they've seen it all – or nearly so.

An ant forages among the florets of a wreath plant.

I've run past wreath plants thousands of times in the chaparral of local open space areas. At a glance, the nondescript wiry brown plant isn't very appealing. But, it's one of a few plants you'll see blooming in the chaparral in the Fall, so on a run this last November I took a closer look. This revealed a lavender-tinged composite flower that is anything but mundane. And, as I was to discover, a case of probable mistaken identity, and an example of one of the ways new species occur.

The photograph is of valley oak savannah on the north slopes of Laskey Mesa in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch). This area was burned in the 2005 Topanga Fire. If you look closely, the condition of the trees varies widely. Some have full crowns; some partial crowns; and some are nearly bare.

Snow Plant (Sarcodes sanguinea) is so different from the norm that each encounter is memorable. In a world where most plants are green, its startling red color and unusual structure always make an impact.

This showy, if somewhat bizarre looking, flower (Clarkia unguiculata) blooms late in the Spring, and is also known by the common name Farewell to Spring.