Shades of purple usually come to mind when one thinks of thistles. However, there are a few white or cream colored thistles. The peregrine thistle (Cirsium cymosum) is a white thistle that is native to California and is only found in its native state and parts of Oregon. Rocky soils, chaparral, mixed evergreen forests and meadows are the preferred habitat of this member of the sunflower or aster family.
The erect spiny stem of peregrine thistle grows between two and five feet high from a tap root. Deeply lobed, spiny leaves with little or no stalk alternate up the stem. Soft hairs coat the upper sides of the leaves while the lower leaf surfaces have coarser hairs. The inflorescence is composed of cream-colored disc flowers. The bracts surrounding the flower head are sticky with short prickles. Sometimes cobwebby fibers also cover the peregrine thistle.
All Cirsium species can be eaten in small amounts. As a child I would often cut various thistles, peel the stems and enjoy a celery-tasting “treat”. I think half the fun involved trying to get a piece of peeled thistle stem without impaling myself on the spines. Only later did I discover that some thistles contain potentially carcinogenic alkaloids. I probably never ate enough thistle to actually do much harm.
Many thistles are not native but have been introduced from other parts of the world, particularly the Mediterranean. Scotch thistle, bull thistle and a host of other thistles reproduce and spread rapidly and aggressively and are therefore considered noxious weeds because they overrun fields, waste areas and other disturbed sites. Those introduced thistles are difficult to eradicate and pose an economic threat to farmers. The native peregrine thistle does not spread quickly and is not the same threat as the introduced species.
These peregrine thistles were growing along Ash Creek near the Lower Campground (Lassen County CA).
Another white thistle that I previously posted is the dwarf or elk thistle.