| Cirsium hydrophilum | |
|---|---|
| Suisun thistle | |
| Conservation status | |
|
Critically Imperiled (NatureServe) |
|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Tribe: | Cynareae |
| Genus: | Cirsium |
| Species: | C. hydrophilum |
| Binomial name | |
| Cirsium hydrophilum (Greene) Jeps. |
|
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.
Contents |
The Cirsium hydrophilum thistle 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 (0.079–0.16 in) long topped with a pappus of about 1.5 centimetres (0.59 in) centimeters.
There are two very localized varieties: