Family: Scrophulariaceae
Buddleja marrubiifolia, commonly known as woolly butterfly bush, is a hardy shrub native to arid regions of northern Mexico and west Texas. It is known for its distinctive silvery, woolly leaves and rounded clusters of golden-orange flowers that attract butterflies, bees, and hummingbirds. This drought-tolerant species is often used in xeriscaping and pollinator gardens, where its bright blooms add color and support beneficial insects. The plant typically grows 3–8 feet tall and wide, forming a dense, rounded shape that fits well in dry, sunny landscapes.
In Hawaiʻi, Buddleja marrubiifolia is not widely cultivated and is not currently known to be invasive. Its seeds have limited natural dispersal, and the species has not shown a tendency to spread beyond planting sites. While it is related to other Buddleja species with known invasive histories in some regions, this particular species is considered low risk. As always, gardeners should plant responsibly—disposing of cuttings properly and monitoring for any unexpected spread—but at this time, woolly butterfly bush does not pose significant threats to Hawaiʻi’s natural areas.
High Risk Traits:
- Congeneric weed – Invasive relatives (B. davidii)
- Broad climate tolerance – Survives wide temperature ranges
- Wind-dispersed seeds – Adapted for wind via capsules
- Intentionally planted – Horticultural use
- Tolerates pruning – Regrows after cutting
Low Risk Traits:
- Not naturalized or weedy – No invasion history
- No spines, allelopathy, or parasitism
- Not shade tolerant – Requires full sun
- Not soil-tolerant – Needs specific alkaline, well-drained soil
- Limited dispersal – Not adapted for water, bird, or animal spread
- Non-toxic – Safe for humans and animals
- No fire risk
- Palatable to livestock – Fair browse
- Herbicide-sensitive – Controllable
