Castilleja rhexiifolia
A hemiparasitic perennial herb in the Orobanchaceae native to western North America, forming dense inflorescences with pink to red-purple bracts and relying on host plants for water and minerals in moist subalpine and alpine meadows, with erect 10–24 inch stems, greenish tubes largely hidden by rose-tinged bracts, and blooms June–September at elevations of 1,800–4,000 m.
Common Names
Splitleaf Indian Paintbrush, Rosy Paintbrush, Rhexia-Leaf Indian Paintbrush, Rhexia-Leaved Paintbrush, Subalpine Paintbrush
Summary
Rhexia-leaf Indian-paintbrush is a hemiparasitic perennial native to western North America, with erect or ascending stems from a woody base and linear to lanceolate leaves 3–6 cm long. It reaches about 10–60 cm in height (range 10–80 cm) and features bracts reddish-purple surrounding a green to purplish calyx and corolla; the inflorescence is a dense spike 2.5–15 cm long, with bracts and flowers colored pink-purple to crimson, blooming May–Sept in moist subalpine to alpine meadows, pond edges, at elevations 1800–4000 m. Distinctive traits include viscid-pilose bracts and color variation, with pollination by Bombus balteatus and other Bombus species.
In cultivation, it prefers mesic, slightly humous, semi-shaded sites with moist, well-drained soil. Propagation is by seed, with physiological dormancy and germination around 98%, via direct seeding or greenhouse-to-nursery production, using a 6:1:1 peat–perlite–vermiculite medium; seedlings reach about 3 cm tall with 15–25 true leaves in roughly 3 weeks and establish within weeks. A host plant is essential for continued growth, commonly Carex hoodii to induce haustoria and hemiparasitism. Uses include ornamental plantings and restoration, and the plant is globally secure (G5).
Lifecycle
Perennial
Height
0.5-2.5 feet
Spread
4-24 inches
Sunlight Requirements
Full sun to partial shade.
Soil Type
Moist soils in meadows, along streams, and in forests
Soil Drainage
Well-drained soils (rocky, gravelly, or sandy loams) that prevent waterlogging.
Soil pH
Acidic soils (pH below 7)
Bloom Color
Pink to crimson (pink-purple to red-purple), with occasional yellow or white.
Bloom Time
Summer
Foliage Color
Green
Fall Foliage Color
Green
Growth Rate
Low
Seasons of Interest
Spring, Summer and Fall
Propagation Methods
Seeds, Cuttings, Division, Layering
Attracts Wildlife
Attracts bees, butterflies, hummingbirds, other pollinators, and birds
Taxonomy
- Taxonomic Rank
- Species
- Author
- Rydb.
Superior Taxa
- Kingdom
- Plantae
- Subkingdom
- Pteridobiotina
- Phylum
- Angiosperms
- Order
- Lamiales
- Family
- Orobanchaceae
- Genus
- Castilleja
Synonyms
Castilleja lanceifolia Castilleja leonardii Castilleja magna Castilleja obtusiloba Castilleja oregonensis Castilleja purpurascens Castilleja subpurpurascens Castilleja humilis Castilleja lauta