Silphium perfoliatum – Cup Plant

SCIENTIFIC NAME: Silphium perfoliatum – Comes from a Greek plant silphion, a
resinous plant that is probably extinct now, and perfoliate meaning a leaf that
wraps around the stem.
FLOWER: Several yellow flowers at the top of the stem, each 2-3 inches across
BLOOMING PERIOD: Late July to early September
SIZE: 3-8 feet tall
BEHAVIOR: Has a central taproot with rhizome-like roots near the base of the stem.
Reseeds easily and may form dense clumps.
SITE REQUIREMENTS: Full sun, but tolerant of light shade, in sandy loamy soil with
wet to moderate moisture. Prairies, stream banks, woods.
NATURAL RANGE: Ontario west to South Dakota, south to Georgia, Mississippi,
Missouri and Oklahoma. In Wisconsin it is found mostly in the southern and
western parts of the state.
SPECIAL FEATURES: The square stem is one distinguishing feature as well as the
pairs of large opposite leaves that “cup” the stem. The cupped leaves hold rainwater
and attract birds and insects seeking a drink. Various birds, especially goldfinches,
are very fond of the seeds. Native Americans made a medical extract from the roots
and the resin was also used as a chewing gum.
SUGGESTED CARE: Water well when planting. A seedling may take several years to
mature. Single plants may flop over.
COMPANION PLANTS: Tall bellflower, Virginia waterleaf, sweet cicely, swamp
buttercup, hairy wood violet, golden Alexanders, Canada anemone, angelica, spotted
joe-pye weed, jewelweed, swamp goldenrod, big bluestem and skunk cabbag