Venus Thistles located on Old Tunnel Road in Grass Valley, CA. First observed in spring of 2012. Two site locations along the road. Site one is on road cut embankment. Soil is sand loam with pine needle litter. Site faces WSW. 25 plants were noted at various stages of growth. Site two is along road but on more level ground. Soil is sandy loam with pine needle litter. Site faces west. One plant at this locality is approx. 36 inches tall. Three other plants are in early germination state. Will add photos from previous observations and current observations.
Seen in bloom near a fire road in a sunny clearing within the wider mixed oak woodland. This specimen is about seventy cm high.
Backyard specimen. No flower spike yet.
The rosette of this new thistle has formed in the past week or so.
This dried Cirsium agrees with the diagnostics of C. occidentale. It is erect and single stemmed with a height of about seventy cm. The leaves and stem are spiny and the ten cm leaf is spiny, clasping and dentate. Dried flower heads are about twenty two mm. This is a native thistle here. The microhabitat is in a sunny dry ridge with rocky soil., within a small clearing of generally chaparral habitat.
O'Neill Ranch Master Plan Draft Environmental Impact Report, February 1995
Found on a hilltop in an oak woodland.
Found aside trail on our way to Grouse Hill. Was growing up next to the underbrush, where lots of sticks and dead down twigs were laying around and caught in the bushes.