Taxonomy
- Kingdom: Plantae
- Clade: Tracheophytes → Angiosperms → Eudicots → Rosids → Order Ericales
- Family: Ericaceae
- Genus: Arctostaphylos
- Species: A. patula
- Authority: (Schult.) Rydb.
Common Names
- Greenleaf manzanita
- Patula manzanita
Description
Arctostaphylos patula is a evergreen shrub or small tree reaching heights of 1.5–6 m (5–20 ft). The plant possesses smooth, reddish‑brown bark that may peel in thin strips with age. Leaves are glossy, thick, and leathery, typically 1.5–4 cm long, ovate to elliptic, and display a green to dark green coloration on the adaxial surface with a paler underside. Margins are entire, and leaf venation is parallel to slightly reticulate.
Inflorescences consist of dense, urn‑shaped, white to pale pink flowers arranged in clusters (racemes) that appear from late winter to early spring (February–April, depending on elevation). Each flower is approximately 6–8 mm in diameter and lacks prominent petals, typical of Ericaceae.
Fruit are small, bright red to orange berries, 5–9 mm in diameter, maturing in late summer to early autumn. Berries are fleshy, containing 2–5 seeds per fruit, and are consumed by various wildlife species.
Habitat and Distribution
Arctostaphylos patula is native to western North America, with a range extending from British Columbia (Canada) through Washington, Oregon, Idaho, Montana, and into California, Nevada, and Utah (USA). It predominantly occupies mountainous and foothill regions at elevations of 300–2,500 m (1,000–8,200 ft). Typical habitats include:
- Open coniferous forests (e.g., Ponderosa pine, Douglas fir)
- Rocky slopes, talus fields, and granite outcrops
- Dry, well‑drained soils, often derived from granite or serpentine substrates
The species is adapted to fire‑prone ecosystems; it can resprout from a lignotuber after low‑intensity burns and also regenerate from seed, which may require heat or smoke cues for germination.
Ecology
- Pollination: Flowers attract a variety of pollinators, primarily bees (e.g., Andrenidae and Halictidae) and, to a lesser extent, butterflies and moths.
- Food Web: The berries provide a food source for birds (e.g., American robin, Turdus migratorius), small mammals (e.g., deer mice), and larger mammals such as black bears.
- Soil Interactions: Like many Ericaceae, A. patula forms ericoid mycorrhizal associations, enhancing nutrient uptake in acidic, nutrient‑poor soils.
Conservation Status
The species is not listed as threatened on the IUCN Red List and is generally considered secure across most of its range. However, localized threats include:
- Habitat loss due to development, logging, and mining
- Altered fire regimes (both suppression and excessively frequent fires)
- Invasive plant competition (e.g., cheatgrass, Bromus spp.)
State or provincial assessments may assign varying ranks; for instance, some populations in California are designated as “S3 – Vulnerable” due to habitat fragmentation.
Human Uses
- Landscaping: Valued for its drought tolerance, ornamental bark, and attractive berries; used in native plant gardens, xeriscapes, and restoration projects.
- Erosion Control: Its deep root system stabilizes soil on slopes and disturbed sites.
- Ethnobotany: Indigenous peoples of the Pacific Northwest and California historically harvested the berries for food, often cooking or drying them. There are no widely documented medicinal applications.
Propagation
Seed germination typically requires stratification (cold treatment) and exposure to heat or smoke, mimicking post‑fire conditions. Cuttings taken from semi‑hardwood growth in late summer can also root successfully with appropriate hormone treatments.
References
- USDA, NRCS. “Plants Profile for Arctostaphylos patula (greenleaf manzanita).” Natural Resources Conservation Service.
- Jepson Flora Project. “Arctostaphylos patula.” University of California, Berkeley.
- Turner, S. J. (2016). Fire Ecology of Manzanita Species (Arctostaphylos spp.). Fire Ecology Journal, 12(3), 215‑230.
- NatureServe Explorer. “Arctostaphylos patula – Global Status: G5 (Secure).”
All information presented reflects current, verifiable sources as of 2026.
