Prairie Thermopsis
Thermopsis rhombifolia
- Native to:
- Canada, United States
Mary Vaux Walcott (en.wikipedia.org)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Fabaceae
- Genus:
- Thermopsis
- Species:
- Thermopsis rhombifolia
- USDA Symbol:
- THRH
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 60 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- High
- Bloom Months:
- may,jun,jul
- Bloom Colors:
- yellow
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★★☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Host Plant for Caterpillars
Filatima ornatifimbriella, Filatima xanthuris, Parectopa thermopsella, Virgin Tiger Moth (Grammia virgo), Orange Sulphur (Colias eurytheme), ⚠️Persius duskywing (Erynnis persius), Queen Alexandra's Sulphur (Colias alexandra), Silvery Blue (Glaucopsyche lygdamus)
Reported Fauna Sightings
Bees: Brown-belted bumble bee (Bombus griseocollis), Central bumble bee (Bombus centralis), Fuzzy-horned bumble bee (Bombus mixtus), Half-black bumble bee (Bombus vagans), Hunt's bumble bee (Bombus huntii), Nevada bumble bee (Bombus nevadensis), Red-belted bumble bee (Bombus rufocinctus), Two-form bumble bee (Bombus bifarius) Hummingbirds: Broad-tailed Hummingbird (Selasphorus platycercus)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies
- Deer Resistant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from deep rhizomes after fire; commonly found in fire-maintained prairie and grassland ecosystems.
Soil Requirements
- Soil Type:
- dry, sandy, well-drained soil
- pH:
- 6.0 - 7.5 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to prairies and open woodlands
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–90 days
- Scarification:
- Seed coat scarification required before sowing
- Germination Time:
- 14–42 days
- Notes:
- Scarification of hard seed coat improves germination. Cold stratification recommended for best results.
The above propagation data sourced from Claude AI
Pre-treatment: Seeds are scarified
Establishment: The plant is commonly found in moist prairies, streambanks and woodlands from the eastern half of the United States to the great Plains and north into Alberta east to Ontario. Seeds are typically collected in small lots, around 0.4 pounds, and hand collected into paper bags.
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 20C. Germinates within 3 months.