Lonicera dioica L.
- En: limber honeysuckle, smooth honeysuckle, glaucous honeysuckle
- Fr: chèvrefeuille dioïque
- Oj: sabankuk
Caprifoliaceae (Honeysuckle Family)
Click on a thumbnail below to see larger image.
General: A perennial, trailing or climbing, woody vine to 3+ m long. Young stems have a waxy, bluish-white (glaucous) coating; older woody stems brown or grayish, with shredding bark.
Leaves: Opposite, simple, pinnately-veined, sessile to petiolate (to 1 cm long) in lower leaves, deciduous. The upper 1–4 pairs of opposite leaves with fused bases (connate-perfoliate), the uppermost pair further modified into a rhombic or elliptic disk that subtends the inflorescence. Leaf blades oblong, ovate, or obovate, 4–12 cm long, 1–6 cm wide; upper surface green, smooth (glabrous); lower leaf surface pale and glaucous, usually glabrous; leaf base tapering (cuneate); apex blunt (obtuse) to rounded; margins entire.
Flowers: Bisexual, in a terminal stalked cluster (spike) of 1–3 whorls of several flowers, subtended by a rhombic or elliptic, connate-perfoliate disk with indented (retuse) to pointed (acute) tips, or abruptly ending in a short, sharp point (mucronate). Calyx minute; corolla greenish-yellow to orange or purplish-red, 1.5 to about 2 cm long, tubular, with a gibbous bulge near the base, ending in 5 oblong lobes arranged in a bilabiate manner, with 3 lobes fused into an upper lip and 2 fused into a lower lip; stamens 5, attached to the inside of the corolla base (epipetalous), filaments hairy toward the base; the single pistil has an inferior ovary and a long-exserted style with a capitate stigma. The outer surface of the corolla and ovary are glabrous. Flowers bloom in early summer.
Fruit: Smooth, orange to red, ovoid berries, sessile, arranged in terminal whorls and subtended by the connate-perfoliate disk. Fruits mature in late summer to autumn.
Habitat and Range: A variety of dry to moist habitats, including open woods, slopes, rocky shores, thickets, and clearings; often in calcareous areas. The glaucous honeysuckle is native to northeastern and central North America. In Ontario, it occurs as far north as the Upper Severn River basin (Soper & Heimburger 1982).
Internet images: The Lonicera dioica webpage from the Connecticut Botanical Society.
The Lonicera dioica webpage from the Robert W. Freckmann Herbarium, Univ. of Wisconsin - Stevens Point.
Similar Species: The only other climbing honeysuckle native to Ontario is Lonicera hirsuta, the hairy honeysuckle, which has somewhat hairy leaves with ciliate margins. Blades of only the upper 1-2 pairs of opposite leaves are connate-perfoliate, with the upper pair modified into a concave disk that subtends the inflorescence. The young stems and lower leaf surfaces of Lonicera hirsuta lack the glaucous coating typical of stems and leaves of Lonicera dioica.
| traits |
Lonicera hirsuta (hairy honeysuckle) |
Lonicera dioica (glaucous honeysuckle) |
| leaf shape |
broadly elliptic, oval, or ovate | narrowly elliptic to oblong |
| leaf surface |
somewhat hairy on both surfaces | smooth, usually glaucous beneath |
| leaf apex |
acute to blunt | blunt to rounded |
| leaf base |
rounded or tapering, upper 1–2 leaves connate-perfoliate |
tapering, upper 1–4 leaves connate-perfoliate |
| leaf margins |
ciliate | entire |
| fruit |
a cluster of orange to red, ovoid berries, subtended by a connate-perfoliate disk | a cluster of orange to red, ovoid berries, subtended by a connate-perfoliate disk |