Clethra alnifolia Linnaeus. Common name: Coastal Sweet-pepperbush, Coastal White-alder. Phenology: Jun-Aug; Sep-Oct. Habitat: Pocosins, blackwater swamp forests, nonriverine swamp forests. Distribution: Primarily a southeastern Coastal Plain species, C. alnifolia ranges from NS and ME south to FL, west to TX; disjunct in sc. TN (Coffee County) (Chester, Wofford, & Kral 1997).
Origin/Endemic status: Native
Synonymy ⓘ: = Can, FNA8, NE, NS, NY, POWO, S, S13, Tn, Tx, Va; = Clethra alnifolia L. var. alnifolia — K4, RAB, Sleumer (1967b); < Clethra alnifolia L. — C, F, G, GW2, Pa, Tat, WH3; Clethra alnifolia L. Basionym: Clethra alnifolia L. 1753
Links to other floras: = Clethra alnifolia - FNA8
Show parent genus | Show parent in key(s)
Wetland Indicator Status:
- Atlantic and Gulf Coastal Plain: FACW (taxonomic split from wetland indicator species)
- Eastern Mountains and Piedmont: FAC
- Great Plains: FACW (taxonomic split from wetland indicator species)
- Northcentral & Northeast: FAC (taxonomic split from wetland indicator species)
Heliophily ⓘ: 6
Hover over a shape, letter, icon, or arrow on the map for definition or see the legend.






















Feedback
See something wrong or missing on about Clethra alnifolia? Let us know here: (Please include your name and email if at all complicated so we can clarify if needed.) We greatly appreciate feedback, and will include updates from you in our next webapp update, which can take a few months. If a species is not keyed, that's because keying is ongoing. Please don't send us feedback about unkeyed species.
Horticultural Information
Intro: Clethra alnifolia, commonly called summersweet, is a rounded, suckering, densely-branched, deciduous shrub that is native to swampy woodlands, wet marshes and stream banks along the East Coast. In late summer this plant develops upright panicles of sweetly fragrant flowers which ripen to into brown seed capsules in the autumn and may persist into winter. The green leaves turn a pleasant yellow to golden-brown in the fall.
Stems:
Leaves:
Inforescence:
Flowers:
Fruits:
Comments:
Height: 3-5 ft.
plant sale text: Coastal sweet-pepperbush blooms profusely in late summer. Its spikes of white flowers produce an intoxicating fragrance that entices people as well as pollinators. Many butterflies are attracted to the nectar of its flowers as are hummingbirds. This adaptable species is easily grown anywhere in sun to light shade, as long as it is planted in soil that retains some moisture. Over time, a single plant will spread to form a clump up to 12 ft wide. This genus supports up to 9 lepidoptera species.
bloom table text: Coastal Sweet-pepperbush can be found along the east coast from Maine to Florida, growing to be 10 feet tall in good soil conditions. A wonderful landscape plant for a shrub border or at the edge of a pond or stream, it grows well in sun or shade and prefers moist, acidic soil. Flowering for 4-6 weeks in July and August, it produces upright white racemes that are very attractive to bees. The fruits are small dry capsules and are often present during much of the year. Coastal Sweet-pepperbush is also noted for its beautiful fall color.
description: Clethra alnifolia, commonly called summersweet, is a rounded, suckering, densely-branched, deciduous shrub that is native to swampy woodlands, wet marshes and stream banks along the East Coast. In late summer this plant develops upright panicles of sweetly fragrant flowers which ripen to into brown seed capsules in the autumn and may persist into winter. The green leaves turn a pleasant yellow to golden-brown in the fall.
stems:
leaves:
inflorescence:
flowers:
fruits:
comments:
cultural notes:
germination code: 2
native range: eastern United States
0 unsaved edits on this page.