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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 acuminate ..... H. annuus

2' Phyllaries generally 1–5 mm wide, acute or gradually acuminate3. Central paleae tipped with stiff white hairs ..... H. petiolaris

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

4' Leaves and phyllaries strigose, 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

6. Leaf blade narrowly lance-ovate to ovate, generally serrate; involucre of larger heads generally 20+ mm diam; fruit 3.5–4.5 mm ..... H. bolanderi

6' Leaf blade lance-linear lance-ovate, generally entire or ± entire (shallowly serrate); involucre of larger heads 15–20 mm diam; fruit 2.7–3.5 mm ..... H. exilis

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

7. Disk corolla lobes red to purple

8. 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

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

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

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

7' Disk corolla lobes yellow

10. Plant from stout taproot

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

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

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

12' Phyllaries <= disk, obtuse to acute ..... H. gracilentus (2) 10' Plant from short rhizome

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

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

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

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

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

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


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

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

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