Illinois Natural History Survey - University of Illinois

Helianthus silphioides
Silphium sunflower, Rosinweed sunflower
Taxonomy

Synonyms: Helianthus kentuckiensis, Helianthus atrorubens var. pubescens

Subspecific taxa:

Classification:

Other taxonomic & nomenclature sources: USDA Plants;  ITIS;  The Plant List;  IPNI

Species Distribution
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More about map & occurrence records

County Map Legend
Absent:
Not known from county
Medium confidence:
Medium or unknown confidence;
often old records or unverifiable observations
Medium-high confidence:
Often observations by expert botanists
High confidence:
Often vouchered herbarium records
Planted / introduced:
Native species introduced outside historic range,
or only in planted locations within county (e.g., restorations)
Historic / extirpated:
Only historic records for the species; likely extirpated
(Note that this category is not yet functional)

North American distribution maps for this species: FLNA;  USDA Plants;  BONAP;  BISON

Collections, Observations & Flowering by Month [?]

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F
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M
0
A
0
M
0
J
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J
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A
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S
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O
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N
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Collections & Observations by Decade [?]

Species Status

Status/Listing: Extinct

Notes:

Origin: Native

Species Description

General: Dicot-herb, perennial

Roots: primary, adventitious, fibrous

Shoots: alternate, opposite leaf arrangment; simple leaf type; entire, undulate leaf margin; Pinnate leaf venation; lanceolate, obovate, oval leaf shape

Inflorescence: head

Flowers: perfect; complete, regular, irregular; yellow; epigynous ovary position

Fruit: achene

Physiology: autotrophic

Reproduction: sexual, vegetative

Ecology & Natural History

Habitat: Species is distributed in borders of woods; upland, dry, open wood, and along roads.

ILPIN Notes: Rodgers, C.E., T.E. Thompson, and G.J. Seiler, 1982. Sunflower species of the United States. National Sunflower Association, Bismark, N.D. 75 pp. Showy species is readily recognized by the leaves which tend to fold longitudinally; stem leaves abrupt contract to a slender petiole; upper leaves always alternate. Involucral bracts rounded at tip, corolla lobes of disk florets dark. Leaf venation may be pinnate or other. Does well in open, sunny gardens, seeds useful in bread, oil, coffee substitute. Disk florets perfect and fertile, ray florets sterile. May have poorly developed rhizomes; has large buds on root crowns.

Functional Relationships:

  • Pollinators: insect
  • Dispersal:
  • Mycorrhizae:
  • N2 fixation:

Human Relationships:

  • Edibility [?] :
  • Showy Flowers: high

Wildlife and Livestock Information:

  • Food Value:
  • Cover Value:

Coefficient of Conservatism (C-value) [?] :

  • Entire State: 10
  • Chicago Area:

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