Silphium laciniatum – Compass Plant

COMMON NAME: Compass Plant
SCIENTIFIC NAME: Silphium laciniatum – comes from Greek silphion referring to a
resinous juice and Latin lanciniatum for “cut” or “lacerated” leaf edges
FLOWER: A cluster of yellow flowers, each 2 – 4 inches across. The individual
flowers have multiple yellow rays and a center disk around an inch wide.
BLOOMING PERIOD: June to August
SIZE: Tall, 3 to 7 feet
BEHAVIOR: This tall plant has interesting basal leaves, stiff and deeply cut. The
leaves may be upwards of 20 inches long and about 10 inches across at the widest
part. The leaves get smaller higher on the stem. Many times the leaves tend to
orient themselves in a north-south direction to reduce the effect of full midday
sunshine, hence the name.
SITE REQUIREMENTS: Grows on rich to moderately dry soils in full sun. Will
tolerate a poor soil. Dry to medium moisture requirement.
NATURAL RANGE: Prairie areas. East of the Mississippi these have mostly
disappeared except for Illinois and southern Wisconsin. The range reaches west to
where the moisture is insufficient, so it’s found only in the eastern parts of Kansas
and Nebraska, for example. In Wisconsin compass plant used to be found along
roadsides and railroad embankments, but has generally disappeared from those
areas.
SPECIAL FEATURES: This plant has a tremendous taproot. Native Americans used
the gummy, bitter resin from broken stems as a mouth cleansing chewing gum. The
flowers attract butterflies and the seeds are favored by goldfinches.
SUGGESTED CARE: Water well during the first season. Plants may not flower for
several years. When they do flower, staking may be needed in garden settings.
COMPANION PLANTS: Big bluestem, heath and smooth asters, rattlesnake master,
showy sunflower, yellow star grass, round-headed bush clover, purple prairie
clover, yellow coneflower, rosinweed, prairie dock, stiff goldenrod and prairie
dropseed