Compass Plant, Robinson's compassplant

Silphium laciniatum

Physical Characteristics

Silphium laciniatum is a PERENNIAL growing to 2 m (6ft) by 0.6 m (2ft in). See above for USDA hardiness. It is hardy to UK zone 4. It is in flower from July to August, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Central N. America - Ohio to Minnesota, south to Alabama and Texas.

Habitats

Cultivated Beds;

Edible Uses

Edible Parts: Edible Uses: Gum A resin exudes naturally from the plant, and can also be obtained by incision[4]. It is an inexpensive substitute for mastic and is used as a chewing gum to sweeten the breath[4, 61, 105, 257]. It forms on the upper part of the flowering stem[183].

Medicinal Uses

Diuretic Emetic Expectorant Tonic Vermifuge The resin obtained from the plant is diuretic[4, 61, 222]. It imparts a strong aromatic odour to urine[4]. A tea made from the roots is vermifuge and a tonic for general debility[4, 61, 222]. It is used as an expectorant in coughs and other pulmonary ailments[4]. A decoction of the smaller roots has been used as an emetic[257]. A tea made from the leaves is emetic, it has also been used in the treatment of coughs, lung ailments and asthma[222].

Known Hazards

There is a report that the plant might be toxic[222].