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

Key to Helianthus

View taxon page for Helianthus

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

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

1. Annual

2. Phyllaries generally 5–8 mm wide, abruptly  ..... H. annuus

2' Phyllaries generally 1–5 mm wide,  or gradually acuminate

3. Central paleae tipped with stiff white hairs ..... H. petiolaris

4. Leaves and phyllaries densely gray-canescent; corolla throat gradually narrowed distally to slightly hairy  bulge ..... subsp. canescens

4' Leaves and phyllaries , green; corolla throat abruptly narrowed distally to densely hairy basal bulge ..... subsp. petiolaris

3' Central paleae glabrous or finely appressed-hairy

5. Paleae acute, = or slightly > disk flowers, glabrous or finely appressed-hairy; leaves densely white-hairy ..... H. niveus subsp. tephrodes (2)

5' Paleae awn-tipped, >> disk flowers, tip glabrous; leaves green ..... H. bolanderi

1' Perennial herb to shrub (occasionally flowering in 1st year)

6. Disk corolla  red to purple

7. Leaves blue-green, glabrous to sparsely short-rough-hairy or bristly, margins often crinkled; roots horizontal, rhizome-like; ray generally 8–9 mm ..... H. ciliaris

7' Leaves green or densely canescent, margins generally flat; plant taprooted; ray generally >> 1 cm

8. Leaves green, short-rough-hairy or bristly; phyllaries <= disk ..... H. gracilentus (2)

8' Leaves densely white-hairy; phyllaries = or slightly > disk ..... H. niveus subsp. tephrodes (2)

6' Disk corolla lobes yellow

9. Plant from stout taproot

10. Shrub, mature stems woody, to 8 cm diam;  and phyllaries generally purplish ..... H. winteri

10' Perennial herb, stems not woody at base; buds and phyllaries generally not purplish

11. Phyllaries >= disk, generally acuminate ..... H. cusickii

11' Phyllaries <= disk,  to acute ..... H. gracilentus (2)

9' Plant from short 

12. Phyllaries generally 3–5 mm wide, tips of outer generally  at maturity ..... H. californicus

12' Phyllaries generally < 3 mm wide, tips ±  to reflexed at maturity

13. Phyllaries generally 2–3 mm wide, tips generally  to reflexed ..... H. inexpectatus

13' Phyllaries generally 1–1.5 mm wide, tips of outer ± spreading to erect ..... H. nuttallii

14. Phyllaries glabrous or strigose; leaves abaxially short-rough-hairy ..... subsp. nuttallii

14' Phyllaries densely hairy; leaves abaxially ± finely  ..... subsp. parishii


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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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