Whorled Rosinweed

Silphium asteriscus var. trifoliatum

Native to:
United States

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Silphium
Species:
Silphium asteriscus var. trifoliatum
USDA Symbol:
SITR7

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
180 cm
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun,jul,aug,sep
Bloom Colors:
yellow

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)

Keystone Species Ranking

Pollen Specialist Bee Keystone:
★★☆☆☆ Native pollen specialist bee species supported by this genus (NWF)

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, birds
Deer Resistant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts vigorously from deep taproot following fire. Historically found in fire-maintained open woodlands and prairies.

Soil Requirements

Soil Type:
rich, well-drained loamy soil
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
good drainage required
Moisture:
dry to moderate
Notes:
prefers open, sunny habitats

Propagation & Germination

Stratification:
Cold/moist stratification required — 60–90 days
Germination Time:
14–30 days
Notes:
Cold stratification improves germination rates. Seeds may germinate erratically without pretreatment.

The above propagation data sourced from Claude AI