Common Name: Compass Plant

General Information

Silphium laciniatum is a herbaceous perennial plant growing from a taproot; it produces a basal clump of leaves in its first year of growth, with flowering stems 100 - 300cm tall from the second year onwards[].
The plant is harvested from the wild for local use as a food and medicine.

Known Hazards

There is a report that the plant might be toxic[].

Botanical References

, ,

Range

Eastern and Central N. America - South Dakota to Ontario and New York, south to New Mexico, Texas and Alabama

Habitat

Prairies, glades and open, disturbed sites; at elevations from 50 - 600 metres[, ]. Calcareous or sandy soils and prairies in Texas[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	2.00 m
Pollinators	Lepidoptera, Insects
Cultivation Status	Wild

Cultivation Details

Silphium laciniatum is a very cold-hardy plant, able to tolerate temperatures down to around -30°c when fully dormant[].
Succeeds in sun or dappled shade, preferring a shady position[]. Succeeds in any ordinary garden soil[]. Prefers a deep moisture retentive moderately fertile soil that is not too nitrogen rich[]. Tolerates poor soils[].
A very ornamental plant[]. Leaves of young plants tip vertically and align themselves north to south to minimise exposure to the midday sun[].
Plants have a deep and extensive root system which makes transplanting difficult[].
The flowers are attractive to butterflies[],

Edible Uses

A resin exudes naturally from the plant, and can also be obtained by incision[]. It is an inexpensive substitute for mastic and is used as a chewing gum to sweeten the breath[, , , ]. It forms on the upper part of the flowering stem[].
The split or broken stems exude a gummy, fragrant-but-bitter resin which was used by Native Americans as a mouth-cleansing chewing gum[].

Medicinal

The resin obtained from the plant is diuretic[, , ]. It imparts a strong aromatic odour to urine[].

A tea made from the roots is vermifuge and a tonic for general debility[, , ]. It is used as an expectorant in coughs and other pulmonary ailments[]. A decoction of the smaller roots has been used as an emetic[].

A tea made from the leaves is emetic, it has also been used in the treatment of coughs, lung ailments and asthma[].

Other Uses

None known

Propagation

Seed - best sown as soon as it is ripe in a greenhouse[]. Prick out the seedlings into individual pots as soon as they are large enough to handle and plant them out in the summer.
Division in spring[]. This is very difficult due to the deep and extensive root system.