Fountain Thistle

All the taxa within Cirsium fontinale have erect stems with leaves very strongly wavy margins. These tall plants may attain a height of 2.2 metres (7.2 ft), but may exist in the form of only 0.5 metres (1.6 ft). A given plant may have one or more stems, and the plants are sometimes short-lived, dying after flowering only once, even though the species is acknowledged to be perennial. Lower leaves are typically petioled or tapered, but mostly spiny-lobed; petioles are either spiny-lobed or toothed. Inflorescences are characterized by prickly heads more or less grouped in a panicle-like cluster, closely subtended by the higher leaves. Involucres are either hemispheric or bell-shaped, with purple to green coloration. Phyllaries range from a lanceolate to ovate shape. There are characteristically many flowers with white, pink or lavender corollae about 20 millimeters in length. Anther bases are sharply sagittate, with oblong tips; the ends of the styles manifest a somewhat swollen node, with a cylindrical superior appendage. The smooth brownish fruits are four to five millimeters in diameter, but distinctly ovoid; many pappus bristles are exhibited.

Varieties. The 3 varieties of Cirsium fontinale have specific limited distribution ranges, and distinctive features.

Cirsium fontinale var. campylon. Cirsium fontinale var. …

The species is endemic to limited regions within northern and central California, at elevations not exceeding 750 metres (2,460 ft). Occurrences appear limited to serpentine seeps and streams within the California Coast Ranges, in areas of the San Francisco Bay Area and of San Luis Obispo County. There are three recognized varieties of this species:

Cirsium fontinale var. campylon — Mount Hamilton thistle; Diablo Range and southern Santa Clara Valley, San Francisco Bay Area. (Federal candidate for listing) Cirsium fontinale var. fontinale — Fountain thistle; San Mateo County. (Federal and State of California Endangered species) Cirsium fontinale var. obispoense — Chorro Creek bog thistle; San Luis Obispo County. (Federal and State of California Endangered species)