A Heat Tolerant Form Of R. occidentale?
Carl A. Deul, Northridge, California
Most everyone is familiar with the many beautiful varieties in the flowers and foliage of R. occidentale. Unfortunately, for one reason or another, persons in the southern and eastern parts of the United States have found it difficult to grow.
Interestingly there is a form of R. occidentale which grows in the San Jacinto Mountains near Idylwild, California, which seems to be much tougher than the forms growing in the coastal areas of Northern California. Several people in the East and South have been growing this form from seed and have found it more tolerant to their conditions than any other form that they have tried. Perhaps this is the heat tolerant R. occidentale people have sought after.
The Southern California Chapter has also found this form of R. occidentale much more tolerant to dry air than any other form they have tried. It grows in canyons or boggy areas at elevations above 1372 m. (4500 feet) that are heavily wooded with cedars. Their roots often run below boulders where the precious moisture is preserved. The air is very dry and the relative humidity is often below 10%. Summer showers are few and far between; temperatures often go as high as 33° C (91° F.)
The flowers are almost pure white, about 6.35 cm (2.5 inches) across and the characteristic yellow blotch is almost nonexistent. The leaves are lanceolate and up to 11 cm (4.33 inches) in length.
There will be seed available through the ARS Seed Exchange that was collected this fall by Bill Moynier and myself.