// SPECIES PROFILE · PERENNIAL · NATIVE

Compass Plant

Silphium laciniatum

Compass plant is the tallgrass-prairie aristocrat — 6-inch deeply lobed leaves at the base orient north-south to minimize midday sun (giving the plant its name), surmounted by 8-foot stalks of large yellow sunflower-like blooms in midsummer.

// QUICK FACTS

Family: Asteraceae
Group: perennial
Native range: Cent. US tallgrass prairie incl. OK
USDA hardiness: Zones 3–9
Mature size: 6–10 ft
Sun: Full sun
Water: Drought-extremely-hardy
Wildlife value: Sunflower-relative blooms feed bees + butterflies; goldfinch eat seeds
Ecological role: deep-rooted prairie giant · tallgrass icon · 100-yr lifespan

Compass Plant (Silphium laciniatum) — *Silphium laciniatum*. Photo via Wikipedia / Wikimedia Commons.

Field Notes

[ growing · ecology · siting · care ]

Roots can drive 15 feet down into prairie soil — virtually impossible to transplant once established, so site it permanently from a small container. May take 3–5 years to bloom but then lives 100+ yrs. The defining indicator species of intact tallgrass prairie.

Why it's on this list: deep-rooted prairie giant · tallgrass icon · 100-yr lifespan. Part of Rooted Revival's NE Oklahoma plant catalog — natives, ecologically positive non-invasive cultivars, and food crops worth growing in the Tulsa region.

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In a tallgrass prairie or pollinator meadow, compass plant pairs naturally with: new jersey tea (Ceanothus americanus), big bluestem (Andropogon gerardii), cowpea / black-eyed pea (Vigna unguiculata), black-eyed susan (Rudbeckia hirta), eastern gamagrass (Tripsacum dactyloides), and prairie blazing star (Liatris pycnostachya).

Combine compass plant with the warm-season grasses listed above for a self-sustaining matrix.

Photo Reference

// Silphium laciniatum — compass plant
Photo: famousmango (iNaturalist, CC-BY-NC)