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 

Having a long-tapered, sharp tip, the sides concave.

..... H. annuus

2' Phyllaries generally 1–5 mm wide, 

acute 

Having a short-tapered, sharp tip, the sides convex or straight and converging at less than a right angle.

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 

basal 

At or near the base of a plant or plant part. Especially said of leaves clustered near the ground or of a placenta confined to the base of an ovary.

bulge ..... subsp. canescens

4' Leaves and phyllaries 

strigose 

With stiff, straight, sharp, appressed hairs.

, 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 

lobes 

1. A major expansion or bulge, such as on the margin of a leaf, sepal, or petal, or on the surface of an ovary. 2. The free tips of otherwise fused structures, such as sepals or petals; larger than teeth.

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; 

buds 

1. An incompletely developed, more or less embryonic shoot, usually covered with bud scales. 2. An unopened flower, often protected by sepals.

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, 

obtuse 

Having a short-tapered, blunt tip or base, the sides convex or straight and converging at more than a right angle.

to acute ..... H. gracilentus (2)

9' Plant from short 

rhizome 

1. In seed plants, stem that is often elongate, more or less horizontal, usually underground; distinguished from roots by bearing of leaves, leaf scars, axillary buds, etc. 2. In ferns, stem that is located underground, embedded in leaf litter, on rocks or in rock crevices, or on trees or tree branches, often scaly or hairy; distinguished from roots by bearing of fronds (roots rarely bear fronds), and their greater diameter.

12. Phyllaries generally 3–5 mm wide, tips of outer generally 

reflexed 

Abruptly bent or curved downward or backward.

at maturity ..... H. californicus

12' Phyllaries generally < 3 mm wide, tips ± 

erect 

Upright; vertically oriented.

to reflexed at maturity

13. Phyllaries generally 2–3 mm wide, tips generally 

spreading 

Oriented more or less perpendicularly to the axis of attachment; often, more or less horizontal.

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 

tomentose 

Covered with densely interwoven, generally matted hairs.

..... subsp. parishii

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