Jepson eFlora: Key page
Vascular Plants of California
Key to families | Table of families and genera

Key to Centaurea

View taxon page for Centaurea

(For a list of species in Centaurea, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Corolla yellow

2. Heads  or subsessile, subtended by leaf-like bracts ..... C. benedicta

2' Heads generally peduncled (if not, then subtending bracts reduced)

3. Corolla 25–30 mm ..... C. sulphurea

3' Corolla generally 10–20 mm

4. Central spine of main phyllaries 5–10 mm, ± purple ..... C. melitensis

4' Central spine of main phyllaries 10–25 mm, straw-colored ..... C. solstitialis

1' Corolla white to pink, blue, or purple

5. Main phyllaries ± spine-tipped

6. Main phyllary tip-spine 6–25 mm

7' Pappus present, 0.3–2.5 mm

8. Involucre body 8–14 mm diam, widely ovoid ..... C. iberica

8' Involucre body 5–10 mm diam, narrowly ovoid ..... C. pouzinii

6' Main phyllary tip-spine 1–5 mm

9. Outer flower corollas expanded, ± ray-like, >> disk flower corollas, 25–35 mm, pink-purple ..... C. diluta (2)

9' Outer flower corollas not or barely expanded, = or slightly > disk flower corollas, 7–13 mm, white to pink or pale purple

10. Involucre 10–13 mm; disk flower corolla 12–13 mm ..... C. diffusa

10' Involucre 7–8 mm; disk flower corolla 7–9 mm ..... C. virgata subsp. squarrosa

5' Main phyllaries not spine-tipped

11. Annual

12. Herbage ± ; disk flower corolla 10–15 mm ..... C. cyanus

12' Herbage  or ± glabrous, sometimes thinly cobwebby; disk flower corolla ± 20 mm ..... C. diluta (2)

11' Biennial or  herb

13. Outer and inner flowers ; corollas all ± equal ..... C. jacea subsp. nigra

13' Outer flowers sterile, inner flowers bisexual; sterile flower corollas > bisexual flower corollas

14. Herbage densely gray-tomentose ..... C. cineraria

14' Herbage ± green, sometimes thinly cobwebby

15' Involucre 15–18 mm

16. Phyllary appendages scarious, light brown, concave to coarsely  ..... C. jacea subsp. jacea

16' Phyllary appendages light to dark brown, flat to ± concave, coarsely dentate to dissected into fine, wire-like  ..... C. jacea nothosubsp. pratensis



Citation for the whole project: Jepson Flora Project (eds.) . Jepson eFlora, [accessed on ]

Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on .

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