The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Anderson's thistle

Habit Plants perennial, (1.5)4–7(10) dm; taprooted, sometimes with creeping roots.
Stems

usually 1, sparsely arachnoid-tomentose to glabrate.

Leaves

elliptic to linear-oblong, 8–20(35) × 2–8 cm, gradually reduced above;

margins coarsely dentate or 1–2-pinnate;

spines 1–5 mm;

surfaces abaxially ± thinly gray-tomentose, adaxially glabrous to sparsely pilose;

basal usually present at flowering, clasping to petiolate.

Involucres

broadly cylindric to narrowly campanulate, 3–5 × 2–4 cm, glabrous to thinly tomentose.

Florets

corollas 30–45 mm, red, occasionally red-purple;

tubes 10–20 mm;

throats abruptly narrowed to tubes, 10–16 mm;

lobes 9–11 mm;

styles conspicuously exserted;

tips 3.5–5 mm, sometimes geniculate.

Phyllaries

without glutinous ridges;

spines weak, 1–3 mm; outer short, linear-lanceolate, appressed;

margins entire or spiny-ciliate;

tips long-acuminate; inner linear; long; entire;

tips red to purple; flat.

Fruits

6–7 mm, brown;

pappi 25–40 mm.

Heads

1–6 per branch;

lateral heads widely spaced along distal portions of branches.

Cirsium andersonii

Distribution
[WildflowerSearch map]
[BONAP county map]
Discussion

Open grasslands, montane woodlands. Flowering Jul–Sep. 1500–2500 m. ECas. CA, NV. Native.

Cirsium andersonii, while currently rare in Oregon, is well documented in northern California and Nevada.

Source Flora of Oregon, volume 2, page 225
Bridget Chipman
Sibling taxa
C. arvense, C. brevifolium, C. brevistylum, C. ciliolatum, C. cymosum, C. douglasii, C. eatonii, C. edule, C. edule x Cirsium remotifolium, C. inamoenum, C. occidentale, C. ochrocentrum, C. remotifolium, C. scariosum, C. undulatum, C. vulgare
Web links