Cirsium hydrophilum
species of plant
Cirsium hydrophilum is a species of thistle which is endemic to California, where it is found only in the San Francisco Bay Area and the Sacramento-San Joaquin River Delta. This native thistle grows in wet boggy habitats.
Description
Cirsium hydrophilum may reach 2 metres (6.6 ft) in height with a branching, cobwebby stem. The leaves are longest near the base of the plant, approaching 90 centimetres (35 in) in length. They are cut into toothed lobes and covered in spines, particularly along the petiole.
The inflorescence bears one or more flower heads, each up to 3 centimetres (1.2 in) long. The head is lined with sticky, twisted, spiny phyllaries and contains pink to purple flowers. The fruit is an achene a 2–4 millimetres (0.079–0.157 in) long topped with a pappus of about 1.5 centimetres (0.59 in) centimeters.
Varieties
There are two very localized varieties:
The rare Cirsium hydrophilum var. hydrophilum, the Suisun thistle, is known from two occurrences in the Suisun Marsh, in the salt marsh habitat of the Delta in Solano County.
Begin with the source’s own compact description: “Cirsium hydrophilum” is species of plant. The dossier treats that line as a proposition to test through Cirsium, hydrophilum and species, not as a finished interpretation.
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This entry incorporates text from “Cirsium hydrophilum” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.