Species Native to Missouri
Common Name: rosinweed
Type: Herbaceous perennial
Family: Asteraceae
Native Range: Central United States
Zone: 4 to 8
Height: 2.00 to 6.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: July to September
Bloom Description: Yellow
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy
Attracts: Birds, Butterflies
Tolerate: Clay Soil
Culture
Easily grown in average, medium moisture, well-drained soils in full sun. Tolerates some light shade. Also tolerates some drought once established. Will grow in a variety of soils including sandy, loamy or clay ones. Plants may be slow to establish in the garden, particularly when grown from seed. Plants often self-seed in optimum growing conditions. Plants develop taproots. Once established, division is not recommended.
Noteworthy Characteristics
Silphium integrifolium, commonly called rosinweed or wholeleaf rosinweed, is a herbaceous perennial native to prairies, glades, railroad right-of-ways, and roadsides in the Midwest and portions of the southern United States. It grows shorter (often to 2-3’ tall) than most of the other native silphiums, though it may grow as tall as 6’. The erect, hairy stems are sparsely clad with pairs of rough, stalkless, hairless or bristly to woolly, medium green leaves (to 6” long) with smooth or finely serrated margins. Leaves are quite variable in shape, ranging from lanceolate to ovate to elliptic. Flowers (to 2-3” diameter) resembling small sunflowers appear in corymb-like inflorescences in mid-summer. Each flower features yellow rays and a yellow center disk. Flowers are subtended by bracts with reflexed tips.
The genus name Silphium comes from the Greek name silphion, used to refer to a resin-bearing plant from northern Africa.
Specific epithet means with entire or uncut leaves.
Problems
No serious insect or disease problems. Downy mildew, leaf spots and rust may occur.
Uses
Best planted in groups where it can naturalize. Some gardeners find it to be too weedy for borders, but others find it to be an effective backdrop for other perennials. Adapts well to prairies, wildflower/native plant gardens, naturalized areas, meadows or moist, open woodland areas.