Friday, March 14, 2014

Additions to the Santa Cruz County Plant Checklist – No. 1 - Jacobaea maritima (Asteraceae)

Jacobaea maritima (L.) Pelser & Meijden subsp. bicolor (Willd.) B.Nord. & Greuter
(=Senecio cineraria DC.)

Sparingly established on the sea bluffs along West Cliff Drive.   Two small colonies are known: one colony is on the bluff face near the junction of Santa Cruz Avenue and West Cliff Drive.  This site is likely the site vouchered by J.H. Thomas 4570A, August 12 1954  “Coastal bluffs about one block west of fishing pier” (RSA185824).

A second larger colony of about 100 various sized plants occurs at “Santa Cruz; West Cliff Drive, just east of the intersection with Farr Avenue, growing on the lip of the coastal bluff”, Dean Wm. Taylor 21458, October 23, 2013 (JEPS).

This attractive shrubby composite is commonly cultivated as “Dusty Miller”.  The taxonomy used here is name based on Taxon 57(3):893-906. 2008.  Subspecies bicolor based on (Willd.) B.Nord. & Greuter - Willdenowia 36(2): 712. 2006.

Thomas 4570A was the first California record.  Specimens labeled as Senecio cineraria are known from 4 other California Counties: Humboldt, Santa Barbara, Ventura and Riverside, the most recent collection obtained in 2010.  This taxon is not treated in the revised Jepson Manual

The Santa Cruz station was not reported in:  D. Neubauer  2013.  Annotated Checklist of the Vascular Plants of Santa Cruz County, California.  California Native Plant Society.

Collectively, the available reports indicate that Jacobaea maritima is capable of persistence in cool, equable coastal California settings and should be considered sparingly introduced.  Persistence is indicated by the 60 year record for Santa Cruz.  At both locations, the plants grow on very steep bluffs directly above cliffs fronting the ocean, and are not under cultivation.