Diervilla lonicera, commonly referred to as Northern Bush Honeysuckle (Low Bush Honeysuckle, Dwarf Bush Honeysuckle, Yellow-Flowered Upright Honeysuckle) is a native deciduous shrub found in the northeastern United States and Canada. Its specific epithet, lonicera (the Latin term for ‘honeysuckle’) refers to its similarity in appearance to the true honeysuckles, genus Lonicera.
Northern bush honeysuckle is a deciduous shrub, reaching a maximum height between 0.6 and 1.2 metres (Sullivan 1993). This particular species is known for the following characteristics: branches lying close to the ground, fibrous roots, pale yellow flowers, and dry, woody fruit. Northern bush honeysuckle's simple leaves are placed in an opposite arrangement. As the seasons change, so do the leaves' colours: initially green, the leaf gradually deepens to a dark red (Jacobs et al., 2009). The flowers are in full bloom between early July and early August; the woody seeds are fully matured by September in preparation for dispersal.
Diervilla lonicera has protogynous flowers (initially female-dominant plant), is well-adapted for pollination, and its stigmas remain receptive after anthesis (fully functioning flower) (Schoen 1977).
Exposed rocky sites, combined with the plant's tolerance for cool climates, dry, or infertile soils are varying characteristics to describe a typical habitat for Diervilla lonicera. It is commonly found in forests dominated by balsam fir (Abies balsamea) and jack pine (Pinus banksiana) (Sullivan 1993). Unlike some plant species that are restricted to specific light conditions, the northern bush honeysuckle is insensitive to changes in light, allowing for broader ranges of habitat. In addition, it is well-adapted to fire-prone habitats, because it can regenerate quickly from underground stems if destroyed by fire. For example, Schoen (1977) found that Diervilla lonicera was the most abundant shrub over a 50-year span on dry ground areas that were destroyed by fire.
Northern bush honeysuckle is found widely spread across most of North America. It grows all along the east coast of the continent, from Northern Quebec and Labrador to Georgia and Alabama and reaches as far west as Saskatchewan. Bush honeysuckle was also introduced to parts of Europe sometime in the eighteenth century, but the exact year is unknown (USDA 2011).
Importance to Humans
Plants from the honeysuckle family are commonly used for herbal cough medicine. The most common use is as an herbal tea for sore throats, but there are also recipes for a cough syrup derived from the leaves and flowers of the vines mixed with honey. Some of these remedies have been able to rival the results of store-bought medicines. It is unknown whether or not Northern bush honeysuckle is any more effective than any other species of bush honeysuckle.
These types of recipes can be found on many online cooking websites, but it is very important to be aware of the dangers involved. Some species of honeysuckle can be poisonous, so it is best to use extreme caution and not be attempted by anyone who is not an expert in this field.
Importance to Ecosystems
The northern bush honeysuckle is a popular food source for a number of animal species. For example, moose consume the shrub and its fruit as a winter food source, whereas white tailed deer consume the plant in both the summer and winter (although preferred in the late summer) (Sullivan 1993). The Diervilla lonicera shrub may also be important for sustaining populations of pollinators. This shrub’s long and flexible style and readily accessible flowers (produced in large quantities) are known to draw significant numbers of bumble bees (Thomson 1980).
Bird species also make use of the shrub. Nests are often constructed from its branches for protection from the elements, and the fruits serve as a readily available food source. Diervilla lonicera may even be responsible for triggering population increases and range expansion among various avian species (McCusker et al., 2009).
Northern bush honeysuckle is generally abundant and widespread in North America; it is only considered to be threatened in Tennessee and rare in Indiana. Neither Canada, nor any of the other American states, has bush honeysuckle registered on a threatened or endangered list (USDA 2011).
Jacobs, B, Lens, F., Smets, E. 2009. Evolution of fruit and seed characters in the Diervilla and Lonicera clades (Caprifoliaceae, Dipsacales). Annals of Bot. 104: 253 –276.
McCusker, C.E., Ward, M.P., and Brawn, J.D. 2009. Seasonal responses of avian communities to invasive bush honeysuckles (Lonicera spp.). Biol. Invasions 12: 2459-2470.
Schoen, D.J. 1977. Floral Biology of Diervilla lonicera (Caprifoliaceae). Torrey Bot. Soc. 104(3): 234-240.
Sullivan, J. 1993. Diervilla lonicera. In: Fire Effects Information System http://www.fs.fed.us/database/feis/plants/shrub/dielon/all.html [accessed 24 October 2011].
Thomson, J. and Plowright, R.C. 1980. Pollen Carryover, Nectar Rewards, and Pollinator Behavior with Special Reference to Diervilla lonicera. Oecologia 46(1): 68-74.
USDA. 2011. United States Department of Agriculture: Natural Resources Conservation Service. [online]. Available from http://plants.usda.gov/java/profile?symbol=DILO [accessed 23 October 2011].