Botanical Name : Silphium laciniatum
Species: S. laciniatum
Synonyms: Compass Plant. Compass-weed. Polar Plant.
Common Names :compass plant or compassplant. prairie compass plant, Pilotweed, polarplant,Gum weed, Cut-leaf silphium, and Turpentine plant.
Habitat; It is native to North America, where it occurs in Ontario in Canada and the eastern and central United States as far west as New Mexico. Western United States, especially Ohio.It grows well on moist soil.
Silphium laciniatum is a perennial flowering plant. This plant is a taprooted herb producing rough-haired stems usually one to three meters tall. The leaves are variable in shape and size, being 4 to 60 centimeters long and one to 30 centimeters wide. The are hairy, smooth-edged or toothed, and borne on petioles or not.Blooming time is late summer to early fall and colour of the flowers are bright yellow. The back of the flower head has layers of rough, glandular phyllaries. The head contains 27 to 38 yellow ray florets and many yellow disc florets. The fruit is a cypsela which can be almost 2 centimeters long and is tipped with a pappus of two short awns.
The common name compass plant was inspired by the “compass orientation” of its leaves. The large leaves are held vertically with the tips pointing north or south and the upper and lower surfaces of the blades facing east or west. A newly emerging leaf grows in a random direction, but within two or three weeks it twists on its petiole clockwise or counterclockwise into a vertical position. Studies indicate that the sun’s position in the early morning hours influences the twisting orientation. This orientation reduces the amount of solar radiation hitting the leaf surface. Vertical leaves facing east-west have higher water use efficiency than horizontal or north-south-facing blades.
Early settlers on the Great Plains could make their way in the dark by feeling of the leaves.
The plant is cultivated in gardens in any ordinary garden soil. Prefers a deep moisture retentive moderately fertile soil that is not too nitrogen rich, in sun or dappled shade. Prefers a shady position. 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.
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.
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 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.
Both Rosin-weed and Compass-weed ate said to be emetic in decoction, and to have effected cures in intermittent fevers, and to have cured the heaves in horses. They are beneficial in dry, obstinate coughs, asthmatic affections, and pulmonary catarrhal diseases. A strong infusion or extract is said to be one of the best remedies for the removal of ague cake, or enlarged spleen, and for internal bruises, liver affections, and ulcers
Other Uses: The Pawnee made a tisane with it. Many groups burned the dried root as a charm during lightning.
Known Hazards : There is a report that the plant might be toxic.
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.