Lonicera involucrata

Twinberry Honeysuckle

Caprifoliaceae

The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Magnoliopsida (dicotyledons). Subclass - Asteridae. Order - Dipsacales. Family - Caprifoliaceae (Honeysuckle family). Genus - Lonicera L. Species - Lonicera involucrata (Richardson) Banks ex Spreng.

Ecology: Twinberry honeysuckle is an upright deciduous shrub that grows up to 3-4 m tall. The leaves are in opposite pairs, egg or broadly lance shaped, pointed, and often hairy beneath. The flowers are tubular, in pairs, and yellow. The double or "twin" shiny black berries that ripen in July or later are cupped by prominent purple-red colored bracts...The bitter ripe berries may be mildly toxic or poisonous to humans. There is some suggestion the foliage or other plant parts may have a mildly toxic effect on cattle.

Twinberry honeysuckle occurs from the sea coast to high elevations in alpine regions. It ranges from Alaska south to Mexico and west through the Rocky Mountain states, as well as most of Canada. The species is adapted to soils that vary from course sand to fine textured silt and clay with a pH of 5 to 8 (moderately high acidity to slightly basic). Found on moist, seasonally wet, and flooded sites, habitats include moist woods, thickets, riparian zones and bogs. It also occurs in brackish tidal swamps and sandy areas along the coast. While tolerant of full sun, twinberry honeysuckle is most commonly found under shady conditions. It will grow on upland soils with moderate fertility but drought tolerance is lacking.

Identification

Twinberry honeysuckle is an upright deciduous shrub that grows up to 12 ft tall. The leaves are in opposite pairs, egg or broadly lance shaped, pointed, and often hairy beneath. The flowers are tubular, in pairs, and yellow (except for the orange-red tinted flowers for the coastal variety ledebourii). The double or “twin” shiny black berries that ripen in July or later are cupped by prominent purple-red colored bracts.

Threats

Among the insect pests are aphids, serpentine leaf miners, and scales. Disease problems have not been widely reported but may include those of other honeysuckles.

Reproduction

Seed is obtained by collecting the ripe berries from July through September then macerating the fruit to separate the seed from the pulp. The seed should be cold moist stratified (moist chilled at 33-36 deg F) for 30 to 90 days in order to overcome embryo dormancy and improve germination. Air dried seed can be stored in sealed containers under cool temperatures for up to 15 years. There is an average of 327,000 seeds per pound. Unstratified seed should be fall sown and covered with a thin layer of soil and 1-2 in. of organic mulch.

Vegetative propagation in containers or beds is easy from hardwood, softwood, and semi-hardwood cuttings, or layering of stems if the soil or growth media is kept moist.

Species Distribution

Citation

OSU College of Agricultural Sciences
Landscape Plants. Lonicera involucrata (online).

USDA Plants Database
USDA, NRCS. 2016. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.

NRCS Fact Sheet
Darris, D. 2011. Plant fact sheet for twinberry honeysuckle (Lonicera involucrata). USDA Natural Resources Conservation Service, Corvallis, OR. 97330.