Prairie Dockm, Prairie rosinweed, Lucy Braun's rosinweed
Silphium terebinthinaceum
Family: Asteraceae or Compositae
What it is like
Silphium terebinthinaceum is a PERENNIAL growing to 1.5 m (5ft) by 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 4. It is in flower from July to August, and the seeds ripen in August. 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.
Height (m): 1.5
Where it is found
Prairies, dry woods and glades.
Eastern N. America - Ontario to Tennessee, Ohio and Indiana.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Gum: can be chewed as a chewing gum or can often be used as a sweetener or thickening agent in foods.
Medicine
Rating: 2
A tea made from the roots is vermifuge and a tonic for general debility. A tea made from the leaves is emetic, it has been used in the treatment of coughs, lung ailments and asthma. A resin in the plant is diuretic.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Emetic: Induces vomiting.
Expectorant: Clears phlegm from the chest by inducing coughing.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Vermifuge: Expels and kills internal parasites.
Other
Rating: 1
A gum or resin that is obtained from the stem can be chewed to cleanse the mouth and teeth.
Gum: Gums have a wide range of uses, especially as stabilizers, emulsifiers, thickening agents, adhesives etc.
How it is grown
Succeeds in any ordinary garden soil. Prefers a deep moisture retentive moderately fertile soil that is not too nitrogen rich, in sun or dappled shade. Succeeds in the wild or woodland garden. Plants have a deep and extensive root system which makes transplanting difficult.
Propagating it: 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.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade;
Habit: Perennial
Hardiness: 4-8
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist