Silphium perfoliatum
(Cup Plant)
Family - Asteraceae
Category - Perennial
Origin - Eastern North America
Year of Introduction - 1766
Season of Interest - Summer, Autumn
Hardiness - H7
Height - up to 2.5m
Width - 1m
Location - The House Border
Description: A tall, clump-forming Perennial with a bushy habit and upright stems. Large, dark green leaves are ovate to triangular in shape and have coarsely toothed margins. The bases of the leaves clasp around the stems forming a cup. Prairie Native Americans used this plant to collect water (hence the common name of 'Cup Plant'. Bright yellow daisy-like flowers have a central crown of golden stamens and a green centre. The flowers are produced in Corymbs at the tips of the tall stems from midsummer into early autumn.
Award of Garden Merit (AGM).
Flower:
Daisy-like flower heads are composed of bright yellow ray florets (petals) with rounded tips, surrounding a crown of golden yellow disc florets and a green centre. Flowers are produced on tall stems from July into September.
Flower colour: Yellow
Flower shape: Daisy-like flowers, disc and ray florets
Flowering time: July, August, September
Foliage:
Large, dark green, ovate to triangular leaves have Dentate margins. The leaves are held in opposite pairs up the tall stems. The bases of the leaves clasp around the stems and form a cup. The stems are four-sided and exude a sticky resin if damaged.
Foliage Senescence: Deciduous
Foliage Shape: Ovate to triangular
Propagation:
Division, seed.
Cultivation:
Best in full sun to partial shade in fertile, moisture retentive soil that is well drained.