Silphium trifoliatum
This tall native Asteraceae perennial features whorled sets of three nearly sessile leaves and abundant yellow ray flowers, blooms from mid-summer through fall in open grassy habitats across the eastern United States, and attracts native bees, butterflies, and birds.
Common Names
Whorled Rosinweed
Summary
Whorled Rosinweed, Silphium trifoliatum, is a tall native perennial of the Asteraceae, native to the eastern United States east of the Mississippi River. It grows about 3 to 7 feet tall with whorled leaves in threes along a smooth stem and bears yellow flower heads from July to September, attracting native bees and butterflies and creating a sculptural presence in open habitats. In cultivation, it prefers full sun to partial shade and well-drained soils, tolerates a dry to moist moisture regime, and is drought-tolerant, hardy in USDA zones 5 to 8. It suits prairies, wildflower/native plant gardens, open meadows, and open woodlands, and spreads by rhizomes or short underground stems to form small colonies.
Lifecycle
Perennial
Height
60-84 inches
Spread
6 feet
Hardiness Zones
Zones 5-8
Sunlight Requirements
Ideally full Sun, tolerates partial sun and partial shade
Soil Type
Well-drained mineral soil
Soil Drainage
Well-drained soil
Soil pH
Mildly acidic to mildly alkaline, tolerates alkaline to around 7, neutral soils are fine
Bloom Color
Yellow
Bloom Time
Summer to early Fall
Leaf Lifecycle
Deciduous
Growth Rate
Medium rate
Seasons of Interest
Summer and Fall
Propagation Methods
Seeds
Attracts Wildlife
Attracts bees, butterflies, and birds
Taxonomy
- Taxonomic Rank
- Species
- Author
- L.
- Publication
- Sp. Pl. : 920 (1753)
Superior Taxa
- Kingdom
- Plantae
- Subkingdom
- Pteridobiotina
- Phylum
- Angiosperms
- Order
- Asterales
- Family
- Asteraceae
- Subfamily
- Asteroideae
- Tribe
- Heliantheae
- Subtribe
- Engelmanniinae
- Genus
- Silphium
Synonyms
Silphium trifoliatum f. trifoliatum Silphium trifoliatum var. trifoliatum