Roundseed St. Johnswort
Hypericum sphaerocarpum
- Native to:
- Canada, United States
Mason Brock ( Masebrock (en.wikipedia.org) )
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Hypericaceae
- Genus:
- Hypericum
- Species:
- Hypericum sphaerocarpum
- USDA Symbol:
- HYSP2
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb , Subshrub
- Height:
- 90 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- jun,jul,aug
- Bloom Colors:
- yellow
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★★☆☆ Butterfly & moth species supported by this genus (NWF)
Host Plant for Caterpillars
Caloptilia hypericella, parallel-banded leafroller (Choristoneura parallela), sparganothis fruitworm moth (Sparganothis sulfureana), Xenotemna pallorana
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies
- Deer Resistant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from rootstock following fire; associated with fire-maintained glades and prairies.
Soil Requirements
- Soil Type:
- rich, well-drained loamy soil
- pH:
- 5.5 - 7.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- consistently moist
- Notes:
- prefers open woodlands and prairies
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–90 days
- Germination Time:
- 14–42 days
- Notes:
- Seeds require light for germination; surface sow and do not cover.
The above propagation data sourced from Claude AI