A massive prairie perennial with leaves oriented north-south (hence "compass"). Yellow sunflower-like flowers atop stems reaching 8 feet. Tap roots descend 15 feet — making them extraordinarily drought-tolerant.
§ Quick facts
§ Encyclopedia
Silphium laciniatum is a species of flowering plant in the family Asteraceae known commonly as compassplant or compass plant. 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. Other common names include prairie compass plant, pilotweed, polarplant, gum weed, cut-leaf silphium, and turpentine plant. It is a rosinweed of genus Silphium.
Source: Wikipedia — Silphium laciniatum Licensed under CC BY-SA 4.0
§ Identification
Field marks. Tall plant with large deeply lobed leaves oriented vertically north-south; yellow sunflower-like flowers atop stems.
Similar species. Other Silphium species (Cup Plant, Prairie Dock).
§ Diet & behavior
Diet. N/A — photosynthesis
Behavior. Tall prairie wildflower with leaves oriented north-south (the source of the common name) — minimizing leaf surface exposure to intense midday sun, an adaptation to prairie conditions.
§ Range
Tallgrass prairie regions
§ Habitat
Tallgrass prairies, open meadows
§ Threats
Tallgrass prairie loss, garden monocultures, deer browsing.
§ Conservation status
According to the IUCN Red List, the compass plant is currently classified as Least Concern.
§ What helps
Plant in deep-soil garden corners. Support prairie restoration. Don't mow prairie plantings.
§ Further reading
- Wikipedia — Silphium laciniatum
- www.nwf.org — authoritative profile of Silphium laciniatum
- iNaturalist · taxon 126781
- IUCN Red List — search for Silphium laciniatum
- GBIF occurrence records
- Encyclopedia of Life — Silphium laciniatum
§ Sources cited
- USDA Plants Database
- Konza Prairie LTER
