Dudleya (2013)

By Eric Driskill (January 2013)

The genus Dudleya has 45 species, which belong to the Crassulaceae family. At one time, Dudleya was included in the Echeveria genus. Now dudleyas form their own genus, which is named after William Russell Dudley, the first head of the botany department at Stanford University.

The plants are almost completely confined to the Pacific coast of the United States from Baja California to as far north as southern Oregon. A few of the species can only be found on some of the islands off the California coast. Most species grow within the winter rainfall region. Their location is a helpful hint as to how to grow these interesting plants.

Dudleyas form rosettes with either flattened or tubular leaves that range from 1 or 2 inches to as large as 2 feet across and tend to form stems over time. Many of the flat, succulent-leaved forms grow as solitary rosettes, while the tubular-leaved species form dense colonies. Several species rare in cultivation lose their leaves altogether during their summer dormancy and retreat to their underground tuberous roots. Their small, star-shaped flowers are often white, yellow or red, and arise from somewhere near the bottom of the rosettes.

The species found most often in cultivation are those heavily coated with dense, white powder (farinose). Most wonder if touching the leaves will disrupt this white powder and leave a fingerprint. Yes, it does. Once disturbed, the leaves will be scarred and retain a blemish until the rosette grows large enough to lose the leaves at the bottom. Please test this on your plant only. I suggest testing on the oldest leaf on the plant.

Possibly the best known dudleya is D. brittonii, which forms a large, dramatic rosette of many narrow, untapered, pointed leaves that are typically pure chalky white. D. anthonyi is quite similar, but with smaller, narrower leaves. A smaller species is D. farinosa, which grows at the northern end of the growing range. Still smaller are D. gnoma and D. gnoma White Sprite.

With plants confined to the winter rainfall region of the west coast, they are winter growers in habitat and often dormant in summer. Overwatering dudleyas in the summer can kill them. Many lose roots in high heat and simply do not have the ability to absorb the moisture during summer months. Care should also be taken to assure water does not pool on the crown of the plants.

Propagation is from seed and stem cuttings. Stem cuttings are most successful when taken from mid-autumn to early winter. Short cuttings do better than longer cuttings. Longer cuttings are older material and take longer to root – often poorly. Avoid propagation during summer months.

Sources:
Dave’s Garden – http://www.davesgarden.com/guides/articles/view/2318
The Timber Press Guide to Succulent Plants of the World – Dortort, F. – 2011
Lexicon of Succulent Plants – Jacobsen, H. – 1977
Succulents Propagation – Kapitany, A.; Schulz, R. – 2004
Cacti and Succulents – Quiros, A.; Young, B. L. – 1974