New York Metropolitan Flora

Common Names

Japanese Honeysuckle,Halls Hon

Field Identification

Semi-evergreen woody vine with opposite simple leaves; fragrant paired white-yellow flowers followed by black berries.

Other uses

(Flint, 1983) (Rehder, 1940)

Used in landscaping situations, hardy to USDA zones 4-5.

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Poisonous properties

(Burrows, 2001)

Although the berries of some species are known to be edible; generally, ingestion of the fruit causes mild to moderate nausea, vomiting, and diarrhea; death is unlikely.

Stories

(Leatherman, 1955)

Lonicera japonica was first introduced into the U.S. on Long Island, New York in 1806 as a horticultural plant.

Nomenclature

Lonicera japonica Thunb., Fl. Jap. 89. 1784.
Caprifolium japonicum Dumont de Courset, Bot. Cult. ed. 2, 7: 209. 1814.
Nintooa japonica Sweet, Hort. Brit. ed. 2, 258. 1830.
Lonicera cochinchinensis G. Don, Gen. Hist. Dichlam. Pl. 3: 447. 1834.
Lonicera acuminata var. japonica Miq., Ann. Mus. Bot. Lugd.-Bat. 2: 270. 1866.
Lonicera fauriei Leveille & Vaniot, Repert. Sp. Nov. Reg. Veg. 5: 100. 1908.
TYPE: unknown

Description

HABIT Perennial, semi-evergreen (losing its leaves only in cold winters), woody vine, monoclinous.

STEMS Main stems prostrate or climbing, round; oldest stems can reach 18 cm in girth Andrews, 1919. Bark smooth on younger stems, fibrous on older stems, not exfoliating, brown to light brown. Twigs brown to light brown, terete, 1-5 mm in diam., with long and unbranched light brown erect or spreading hairs, sparsely to densely distributed apically, eglandular. Pith absent, hollow in older stems, nodal diaphragm present. Sap translucent. The lateral branches that sprawl along the soil root at the nodes Hardt, 1986. Has a dense root system that may extend laterally for a distance of 3 meters and attain depths of meter Leatherman, 1955. For a detailed analysis of the root anatomy see [4710]. For a study of the xylem see Chiu, 1992.

BUDS Axillary only, scattered along stem; axillary buds 1 per axil, ovoid. Bud scales imbricate. Bud scale scars not encircling the stem. Leaf scars thinly crescent-shaped. Vascular bundle scars 3.

LEAVES Opposite, simple, spiral, 2 per node (reports of fasciation with 3-10 leaves per node Broadhurst, 1909), spaced somewhat evenly along stem, divergent from stem. Stipules absent. Leaves petiolate, petiole flattened, 0.4-1 cm long, with long and unbranched hairs, erect or spreading, moderately dense or dense, distributed throughout; not glabrescent, eglandular. Leaf blades: abaxial surface light green, adaxial surface green, lanceolate or ovate, bilaterally symmetric, 3-8 cm long, 1.5-4 cm wide, base cuneate or obtuse, margin entire or occasionally shallowly-lobed 1/4 - 1/2 the distance to the midvein. Apex acuminate or acute, abaxial surface with long and unbranched hairs, erect or spreading, light brown, moderately dense, distributed throughout, eglandular. Adaxial surface with long and unbranched, erect or spreading, light brown hairs, sparsely distributed throughout, eglandular (L. japonica var. chinensis has nearly glabrous leaves). For an investigation of plasticity of stomatal and trichome densities see Caiazza, 1980.

INFLORESCENCES Bisexual, axillary paired cyme subtended by foliaceous bracts. Peduncle 0.5-3 cm long, moderately to densely hairy. Rachis absent, flowers sessile at peduncle apex. Bracts petiolate, light green, ovate, margin ciliate, abaxial surface with long and unbranched hairs, eglandular. Bracteoles 2, green, oblanceolate or elliptic or oblong, 2 mm long, 1 mm wide, margin ciliate, apex obtuse, with long and unbranched hairs, eglandular.

FLOWERS Serotinous, formed on last season's growth, bisexual, with sepals and petals readily distinguishable from one another, 5-merous, 2 flowers per inflorescence, fragrant, perianth of two whorls. Calyx actinomorphic, of fused sepals, persistent, abaxial and adaxial surfaces green, tube 2.5-3 mm long, 1-1.5 mm wide, glabrous. Sepal lobes 5, linear triangular, margin ciliate, apex acute, glabrous, eglandular. Corolla zygomorphic, infundibuliform to bilabiate, of fused petals, deciduous, abaxial and adaxial surfaces light yellow to white, occasionally tinged with rose-pink (L. japonica var. chinensis has a red corolla); 35-55 mm long, externally hairy and sparsely glandular. Petal lobes 5. Margin entire, apex obtuse, interior of tube with long and unbranched hairs, eglandular, exterior of tube glabrous or with long and unbranched hairs, eglandular. Gynoecium syncarpous. Locules 2-3. Stigmas 1, capitate. Styles 1, 40- 50 mm long, glabrous. Ovary inferior, 2.5 mm long, 1.5 mm wide, glabrous. Placentation axile. Androecium epipetalous, exserted, haplostemous, inserted near the top of the corolla tube. Stamens 5. Anthers opening along the long axis, yellow, glabrous, eglandular. Filaments straight, light yellow, glabrous, eglandular.

FRUITS Bacca, black, globose, 5-7 mm in diameter, glabrous, eglandular.

SEEDS Seeds 2 to 13, dark brown, ovoid, 2.5-3 mm long, 2 mm wide, glabrous, eglandular, reticulate-foveate.

Habitat

Leatherman, 1955

Widely adaptable, found in dry to wet situations in sun or shade; including woods, thickets, fields, fence rows, swamps, roadsides, and urban woodlots.

Distribution

Indigenous to eastern Asia, naturalized throughout the United States except the Pacific Northwest.

United States -- AL, AR, AZ, CA, CO?, CT, DE, FL, GA, HI, IA?, IL, IN, KS, KY, LA, MA, MD, MI, MN?, MO, MS, NC, NE, NH, NJ, NM, NV, NY, OH, OK, PA, RI, SC, TN, TX, UT, VA, VT?, WI, WV

Canada -- ON?, QC?

New York Metropolitan Region -- Nonnative, naturalized throughout the metropolitan region.

Rarity Status

Global Heritage Rank -- G5

Species Biology

Flowering

June [week 1] - July [week 4] (with sporadic flowering until November)

Pollination

(Roberts, 1979) (Graenicher, 1900)

Mellitophily -- Apis, Bombus, Andrena?, Halictus?, Megachile?, Osmia?
Probably:
Mycophily? -- Mesogramma?
Phalaenophily? -- Hemaris?
Ornithophily? -- Trochilus? (Hummingbird)

Fruiting

September [week 1] - December [week 1]

Dispersal

(Ridley, 1930) (Martin, 1951) (Hardt, 1986) (Suthers, 2000) (Ingold, 1983)

Endozoochory -- Avian Frugivores: Corvus vulgaris (Crow), Turdus migratorius (Robin), Meleagris gallopava (Turkey), Colinus virginianus (Bobwhite Quail), Sialia sialis (Eastern Bluebird), Catharus guttata (Hermit Thrush), Zonotrichia albicollis (White-throated Sparrow), Carpodacus purpureus (Purple Finch), Carduelis tristis (Goldfinch), Junco hyemalis (Junco), Catharus minima (Gray-cheeked Trush), Catharus ustulatus (Swainson's Thrush), Dumetella carolinensis (Gray Catbird), Bombycilla cedorum (Cedar Waxwing), Cardinalis cardinalis (Cardinal), Mimus polyglottus (Mockingbird), Dendroica coronata?(Yellow-rumped Warbler), Toxosoma rufum? (Brown Thrasher), Cyanociita cristata? (Blue Jay)

For an analysis of late-ripening nonnative species effects on avian migration, range, and survival see (White, 1992)

Germination

(Schopmeyer, 1974) (Leatherman, 1955)

Natural germination is believed to occur in the spring following autumn/winter dispersal. Germination is epigeous. Seed viability is highly variable. One study found that 85% of seed were viable and obtained 63% germination.