E-Flora BC: Electronic Atlas of the Flora of BC

Cirsium drummondii Torr. & A. Gray
Drummond's thistle (dwarf thistle)
Asteraceae (Aster family)

Introduction to Vascular Plants

Photograph

Map

Distribution of Cirsium drummondii
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Species Information

General:
Biennial herb from a taproot; stems erect, branched, thick, fleshy, woolly-hairy, simple, 1.2-3.0 m tall.

Leaves:
Basal and stem leaves narrowly oblanceolate to lanceolate, lobed 1/2 or 3/4 the width of the blade, segments oblong-triangular, margins of the segments with 3-5 slender spines, the upper surface glabrous to soft-hairy, the lower surface unevenly hairy, the uppermost leaves narrower, ascending, extending beyond the compact group of heads.

Flowers:
Heads discoid, 1-9, in a terminal cluster; involucres egg-shaped, 3-5 cm tall; involucral bracts glabrous, glandular, graduated, outer ones egg-shaped, tapering to a stout, 2-3 mm spine, inner ones progressively narrower with a broadly dilated, papery, irregularly-margined tip; disk flowers purplish-red, 30-44 mm long, the tubes 20-30 mm long, the lobes 5-7 mm long.

Fruits:
Achenes 4-5.5 mm long, straw-coloured with a light apical rim; pappus whitish, becoming yellowish at maturity, shorter than the corollas by 1-8 mm.

Source: The Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source: The Illustrated Flora of British Columbia

Habitat and Range

Mesic to dry roadsides, meadows and forest openings in the steppe and lower montane zones; frequent in SC and SE BC, rare in the Peace River area; E to ON and S to WY.

Source: The Illustrated Flora of British Columbia

Status Information

Origin Status	Provincial Status	BC List (Red Blue List)	COSEWIC
Native	S3S4	Yellow	Not Listed

BC Ministry of Environment: BC Species and Ecosystems Explorer.

Synonyms

Synonyms and Alternate Names:
Cirsium coccinatum Osterh.

Taxonomic Keys

TAXONOMIC KEY TO CIRSIUM

1. Heads small; involucres 1-2 (rarely 2.5) cm tall; plants introduced.

2. Stems distinctly spiny-winged; plants with perfect flowers C. palustre
2. Stems not conspicuously spiny-winged; plants partly of male and female flowers........ C. arvense

1. Heads large; involucres more than 2 cm tall; plants native (except C. vulgare).

3. Leaves bristly-spiny above, stems distinctly spiny-winged............ C. vulgare
3. Leaves cobwebby to loosely woolly-hairy, woolly or nearly glabrous above, stems not spiny-winged.

4. Pappus of mature seeds exceeding the corollas by 1-10 mm.............. C. foliosum
4. Pappus of mature seeds shorter than the corollas.

5. Heads large; involucres 3-5 cm tall........... C. drummondii
5. Heads small; involucres less than 3 cm tall.

6. Outer involucral bracts more than 2 mm wide at base, slightly if at all hairy and if so, then mainly marginal.

7. Outer involucral bracts strongly glandular; lowermost leaves deeply pinnately lobed more than 1/2 the width of the blade.............. C. undulatum
7. Outer involucral bracts without glands; lowermost leaves shallowly pinnately lobed to 1/2 or less the width of the blade............... C. scariosum

6. Outer involucral bracts less than 2 mm wide at base, densely cobwebby.

8. Corollas white or creamy-white, rarely pinkish; involucral bracts greenish............. C. hookerianum
8. Corollas purplish-red to purplish-pink; outer involucral bracts purplish.

9. Styles exceeding the corollas by at least 3 mm; achenes 5-6.5 mm long; leaves usually lobed more than 1/2 the width of the blade.............. C. edule
9. Styles nearly equal to or exceeding the corollas by only 1.5 mm; achenes 4-4.5 mm long; leaves usually lobed less than 1/2 the width of the blade................. C. brevistylum

Source: Illustrated Flora of British Columbia