Cirsium douglasii is a species of thistle known by the common names Douglas' thistle and California swamp thistle.[1] [2]
It is native to the central coast and northern California ranges, foothills, and plateaus, and adjacent parts of southern Oregon and northwest Nevada.[3] It grows in wet places in a number of types of habitat.[4]
This native thistle, Cirsium douglasii, is a biennial or short-lived perennial herb growing up to 2.5m (08.2feet) tall, with a branching woolly stem. The longest gray-tomentose leaves, located about the base of the plant, are up to 1m (03feet) long. They are sometimes lobed or toothed and are borne on a spiny petiole.[5]
The inflorescence is a cluster of several flower heads surrounded by small leaves. Each flower head is up to 3cm (01inches) long and lined with purple-tipped spiny phyllaries. The head contains purple or white flowers. The fruit is a dark-colored achene 2mm4.5mm long/diameter with a pappus which may reach 2cm (01inches) in length.[5]
