Cox, Paul
Silphium laciniatum L.
Compassplant, Compass plant
Asteraceae (Aster Family)
Compassplant is a tall, coarse, sunflower-like
perennial, growing 3-12 ft. high. Deeply cut, hairy leaves, up to 2 ft. in length, usually orient themselves north and south to avoid the heat of the noonday sun. Scattered along the top half of the stout, sticky
stem are 2-5 in. wide, yellow, radiate flowers. A tall plant bearing yellow flower heads with large, hairy-edged, green bracts;
stem exudes resinous
sap
Compass Plant is one of a group of tall, mostly prairie sunflowers, some with very large leaves. The common name refers to the plants deeply incised leaves, which tend to be oriented in a north-south direction. The hardened
sap of this plant can be chewed like gum. Rosinweed (
S. integrifolium) has
opposite, very rough, stalkless, untoothed or slightly
toothed leaves and is 2-5 (60-150 cm) tall. Cup Plant (
S. perfoliatum) has
opposite leaves that envelop its square
stem, each leaf forming a cup around it. Prairie Dock (
S. terebinthinaceum) has large,
ovate or heart-shaped, basal leaves to 2 (60 cm) long; the sparsely leaved flower stalk sometimes reaches a height of nearly 10 (3 m).
Image Gallery:
14 photo(s) available
Plant Characteristics
Duration: Perennial Habit: Herb Leaf Retention: Deciduous Flower:
Fruit: Size Class: 3-6 ft.
Bloom Information
Bloom Color: Yellow
Bloom Time: Jul , Aug , Sep
Distribution
USA: AL , AR , CO , IL , IN , IA , KS , KY , LA , MI , MN , MS , MO , NE , NM , NY , ND , OH , OK , PA , SD , TN , TX , VA , WI , DC
Canada: ON Native Distribution: OH to LA, w. to e. Great Plains
Native Habitat: Prairies
USDA Native Status: L48(N), CAN(N) Growing Conditions
Light Requirement: Sun
Soil Moisture: Dry
Drought Tolerance: High
Soil Description: Various well-drained soils.
Conditions Comments: Compass plant has a large, woody
taproot that may reach down 15 ft. Slow-growing, long-lived, eye-catching, sunflower-like blooms. (Ontario
Native Plants 2002)
Benefit
Use Wildlife: The large seeds are favored by birds and small mammals.
Conspicuous Flowers: yes
Attracts: Birds , Butterflies
Nectar Source: yes
Last Update: 2012-12-09
