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musk thistle, nodding thistle

compact-headed thistle, Italian thistle

Habit Plants annual or biennial, 4–20+ dm. Plants annual, 2–20 dm.
Basal leaves

10–40 cm, 1–2-pinnate.

10–25 cm, deeply lobed or pinnatifid.

Cauline leaves

lanceolate to elliptic or linear, 4–25 cm, shallowly to deeply lobed or pinnate;

lobe margins and tips spiny;

surfaces glabrous or tomentose.

obovate or oblanceolate to linear-elliptic, 4–15 cm, shallowly or deeply lobed or pinnatifid;

lobe margins and tips spiny;

surfaces abaxially tomentose, adaxially hispid-pustulose.

Involucres

hemispheric, 20–60 mm in diameter.

cylindric or ellipsoid, 10–25 mm in diameter.

Disc florets

corollas 15–28 mm, purple.

corollas 14–16 mm, purple.

Phyllaries

broadly or narrowly lanceolate; midribs prominent.

narrowly lanceolate;

margins not membranous; midribs prominent.

Fruits

4–5 mm, tan or brown;

pappus bristles 13–25 mm.

4–6 mm, tan or brown;

pappus bristles 15–20 mm.

Heads

solitary or in pairs, often nodding;

peduncles not winged.

2–5 per cluster;

peduncles winged.

2n

=16.

=54, 60, 62.

Carduus nutans

Carduus pycnocephalus

Distribution
[WildflowerSearch map]
[BONAP county map]
[WildflowerSearch map]
[BONAP county map]
Discussion

Disturbed areas, clearcuts. Flowering Jun–Oct. 0–1900 m. Col, ECas, Owy, WV. CA, ID, NV, WA; throughout most of North America; Asia, Europe. Exotic.

Disturbed areas, waste areas, riverbanks. Flowering May–Jul. 50–700 m. CR, Sisk, WV. CA, ID; widely scattered in US; Asia, Europe. Exotic.

Source Flora of Oregon, volume 2, page 211
Kenton Chambers
Flora of Oregon, volume 2, page 211
Kenton Chambers
Sibling taxa
C. acanthoides, C. crispus, C. pycnocephalus, C. tenuiflorus
C. acanthoides, C. crispus, C. nutans, C. tenuiflorus
Synonyms Carduus pycnocephalus ssp. pycnocephalus
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