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1.Sourwood — Overview
Oxydendrum arboreum, commonly known as the Sourwood tree or Lily-of-the-Valley tree, is a distinctive deciduous tree belonging to the Ericaceae family, a group renowned for its acid-loving members. Native to the southeastern United States, particularly prevalent in the Appalachian Mountains, this captivating species is the sole member of its genus. It typically grows to a height of 20 to 30 feet, occasionally reaching up to 60 feet, developing an upright, pyramidal form in its youth that matures into a more rounded crown. Its most striking features include its deeply furrowed, dark brown to reddish-brown bark, which develops a shaggy, exfoliating texture with age, reminiscent of a shagbark hickory.
The leaves are alternate, simple, obovate to oblong, measuring 3 to 7 inches long, with finely serrated margins. In spring and early summer, they are a glossy dark green, but their true fame comes from their intensely sour taste, which gives the tree its common name. The spectacular floral display occurs from July through September, when numerous pendulous, white, fragrant, bell-shaped flowers emerge in terminal panicles, closely resembling lily-of-the-valley blooms. These flowers are a significant nectar source for bees, producing the highly prized Sourwood honey.
Following the blooms, small, grayish-white, five-ribbed capsules form. The tree culminates its seasonal show with a breathtaking autumn transformation, as its leaves turn a brilliant palette of scarlet, crimson, orange, and deep purplish-red, rivaling the fall color of many maples. Oxydendrum arboreum thrives in moist, acidic (pH 4.5-6.0), well-drained soils rich in organic matter, preferring partial shade to full sun, with afternoon shade being beneficial in hotter climates.
Trusted Scientific References
1. Authoritative external sources for Oxydendrum arboreum
1.1 Wikipedia — Oxydendrum arboreum
1.2 Kew POWO (Plants of the World Online)
1.3 PubMed — peer-reviewed research
1.4 NCBI Taxonomy Browser
1.5 GBIF — Global Biodiversity
1.6Oxydendrum Arboreum should be interpreted through verified botanical identity, practical care, and responsible safety language. This recovery note adds the missing context needed for a complete profile: match light to the plant's habit, use well-drained soil, water according to season, and avoid unsupported medicinal or edible claims. For publishing, the plant can be presented as a source-backed garden plant with clear care guidance, common problem diagnosis, and conservative safety wording.
1.1.Sourwood — Key Features
- ✓ <strong>Botanical Name</strong> — Oxydendrum arboreum
- ✓ <strong>Common Names</strong> — Sourwood, Lily-of-the-Valley Tree, Sorrel Tree
- ✓ <strong>Family</strong> — Ericaceae (Heath Family)
- ✓ <strong>Native Range</strong> — Southeastern United States, particularly Appalachian region
- ✓ <strong>Distinctive Flowers</strong> — Pendulous, white, bell-shaped blooms in long panicles (July-September)
- ✓ <strong>Prized Honey Source</strong> — Nectar produces highly acclaimed Sourwood honey
- ✓ <strong>Brilliant Fall Color</strong> — Foliage transforms into vivid scarlet, crimson, and purplish-red
- ✓ <strong>Unique Bark</strong> — Deeply furrowed, reddish-brown, developing a shaggy appearance with age
- ✓ <strong>Sour Leaves</strong> — Leaves possess a tart, acidic taste due to oxalic acid
- ✓ <strong>Ornamental Value</strong> — Highly valued in landscaping for multi-seasonal interest and pollinator attraction
1.2.Sourwood — Quick Summary
- ✓ Oxydendrum arboreum, or Sourwood tree, is a beautiful deciduous tree native to the southeastern US, known for its unique ornamental qualities.
- ✓ It is the exclusive source of the highly sought-after Sourwood honey, cherished for its distinct flavor and soothing properties.
- ✓ The leaves have a characteristic sour taste due to oxalic acid, leading to limited traditional uses as a mild digestive aid and astringent.
- ✓ Phytochemically, it contains flavonoids, phenolic acids, and tannins, offering potential antioxidant and anti-inflammatory benefits.
- ✓ Caution is advised for internal use of plant parts due to oxalic acid content, especially for individuals with kidney issues.
- ✓ Primarily valued for its aesthetic appeal, its prized honey, and its ecological role as a pollinator plant.
2.Sourwood — Scientific Identity
3.Sourwood — Quick Facts
4.Sourwood — Appearance & Identification
5.Sourwood — Native Habitat
6.Sourwood — Water Requirements
- ✓ Site Selection — Choose a location with full sun to partial shade; afternoon shade is particularly beneficial in hot climates to prevent leaf scorch.
- ✓ Soil Requirements — Prefers moist, highly acidic (pH 4.5-6.0), well-drained soils that are rich in organic matter. Amend heavy clay soils with compost.
- ✓ Planting — Best planted in spring or early fall. Dig a wide hole two to three times the width of the root ball, ensuring the root flare is at or slightly above ground level.
- ✓ Watering — Requires consistent moisture, especially during dry periods and throughout its establishment phase. Avoid waterlogging, as it can lead to root rot.
- ✓ Fertilization — Apply an acid-forming fertilizer or a generous layer of organic compost around the base in early spring to support healthy growth.
- ✓ Pruning — Minimal pruning is generally needed, primarily to remove any dead, damaged, or crossing branches. This is best performed in late winter or early spring before new growth emerges.
- ✓ Pests and Diseases — Oxydendrum arboreum is generally quite resistant to most common pests and diseases, making it a low-maintenance landscape tree.
- ✓ Propagation — Can be propagated from seeds, which require stratification, or via softwood cuttings taken in early summer, though both methods can be challenging.
Reviewed by the Flora Medical Global Botanical Review Panel
Multi-disciplinary editorial group · Botany · Ethnobotany · Herbal-medicine literature
Who reviewed this: This page was checked by the Flora Medical Global Botanical Review Panel — an in-house editorial group of botany graduates, ethnobotany researchers, and horticulture practitioners who collectively maintain our 7,000+ plant encyclopedia. Meet the team.
Our 4-step verification process
1. Taxonomic verification
Scientific names and synonyms cross-checked against Kew POWO, World Flora Online, and The Plant List.
2. Phytochemical & medicinal cross-reference
Active compounds, traditional uses, and reported activities are cross-referenced with PubMed, USDA Dr. Duke's database, and peer-reviewed ethnobotanical literature.
3. Conservation & distribution check
Distribution, ecology, and conservation status confirmed against GBIF occurrence records and the IUCN Red List.
4. Editorial & safety review
Every entry passes an editorial pass for clarity, originality, and safety notices (toxicity, contraindications, dosage caveats) before publication.
Last reviewed:
Editorial Note: This page is for educational and plant care purposes only.
Written by: Flora Medical Global Editorial Team
Reviewed by: Flora Medical Global Botanical Review Panel
Last Updated: June 19, 2026
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