Hookedspur Violet
Viola adunca
- Native to:
- Canada, Greenland, Labrador, Mexico, United States
brewbooks (www.flickr.com) from near Seattle, USA






Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Violaceae
- Genus:
- Viola
- Species:
- Viola adunca
- USDA Symbol:
- VIAD
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 15 cm
- Light Requirements:
- Shade
- Drought Tolerance:
- Medium
- Bloom Months:
- mar,apr,may,jun,jul,aug
- Bloom Colors:
- purple, violet, blue
- Ground Cover:
- Yes
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)
- Pollen Specialist Bee Keystone:
- ★★★★★ Native pollen specialist bee species supported by this genus (NWF)
Host Plant for Caterpillars
Atlantis fritillary (Speyeria atlantis), ⚠️Bog Fritillary (Clossiana eunomia), Edwards' fritillary (Speyeria edwardsii), Great Basin fritillary (Speyeria egleis), Great Spangled Fritillary (Speyeria cybele), Hydaspe fritillary (Speyeria hydaspe), Mormon fritillary (Speyeria mormonia), Titania's fritillary (Clossiana titania), 🛑Zerene fritillary (Speyeria zerene)
Garden & Ecology Notes
- Wildlife Value:
- butterflies, bees
- Deer Resistant:
- Yes
- Fragrant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from rootstock following fire; often increases in abundance in early post-fire communities.
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 woods and meadows
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–90 days
- Germination Time:
- 14–60 days
- Notes:
- Seeds require light for germination. Fresh seed germinates more readily than stored seed.
The above propagation data sourced from Claude AI
Pre-treatment: 120 days of cool (38F)/moist stratification
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 4C for 3 months, then place @ 20C for 3 months.