Lonicera japonica Thunb., japanese honeysuckle. Perennial vine, evergreen, typically not twining but with terminal shoots long–arching or vinelike sprawling over neighboring shrubs (scandent) and over low vegetation; shoots with only cauline leaves and stems with long internodes, mostly 2–dimensional (plagiotropic) via petiolar twisting, short–hairy and with capitate glandular hairs, the glandular hairs erect with orangish to translucent reddish purple heads on colorless stalk but head commonly lost in age leaving only stalk.
Stems cylindric, green or purplish red, short–hairy and with stalked glandular hairs, older stems with red–brown periderm.
Leaves opposite decussate, simple, petiolate with pair connected by low ledges across node, without stipules; petiole hemi–cylindric, 5—15 mm long, conspicuously short–hairy; blade ovate to oval, < 40—110 × < 20—57 mm, subtruncate sometimes slightly oblique at base, entire and ± short–ciliate with arching, ascending hairs on margins, not inrolled, acute to rounded at tip, pinnately veined with midrib sometimes raised but minor veins slightly sunken on upper surface and all principal veins raised on lower surface, surfaces with conspicuous netted venation, upper surface dark dark green and not glaucous, minutely bumpy (convex cells (10×), short–hairy glabrescent along veins and near margins, lower surface with arching hairs also along principal veins.
Inflorescence leafy with flowers in 2–flowered cymes, cymes paired and axillary at successive nodes on short axillary shoots at node, first with a pair of bracts appearing like miniature leaves, flowers sessile and touching but not fused, bracteate; peduncle to 13 × 1 mm, green, villous with scattered, stalked glandular hairs, the hairs to 0.5 mm long often with more than 1 stalk cell, flowers on a cyme at a node opening on different days; bracts subtending flowers 2 and opposite, leaflike and petiolate, petiole to 4 mm long, blade broadly elliptic, 11—13 × 7.5—9 mm, rounded to acute at tip, villous and with scattered, stalked glandular hairs; bractlets subtending flower 2, opposite on outer faces, appressed to ovary, round to obovate and cupped, ± 1 × 1 mm, green, conspicuously ciliate on margins, with pustulate short hairs on outer (lower) surface and appressed short hairs on inner surface.
Flower bisexual, bilateral, 9—12 mm across (corolla), strongly sweet fragrant; calyx unequally 5–lobed, on top of ovary, crownlike, ca. 1 mm long, green; tube ± 0.25 mm long, the thickest next to ovary; lobes subequal, triangular, 0.4—0.8 mm long, short–ciliate on margins; corolla 2–lipped, 5–lobed, in range < 45—57 mm long, with lips divergent from at or just below midpoint, white aging cream–colored eventually pale light yellow to pale orange, outer surface with scattered short–pilose hairs and stalked glandular hairs; tube slight cylindric, 24—27 × 2 mm diameter, not pouched at base, inner surface lined with white pilose hairs; upper lip appearing to be 4–lobed, ascending, wedge–shaped to rectangular in outline, to 15 × 10 mm, lobes similar and overlapping, linear 13—21 × 3.5—4 mm; lower lip appearing 1–lobed, initially projecting outward soon recurved nearly a full coil, unlobed, strap–shaped (wide–linear), ca. 25—34 × 3 mm, relatively flat, rounded at tip; stamens 5, long–exserted; filaments fused along corolla tube and free 1—1.5 mm from top, free portion projecting from upper side of corolla tube somewhat horizontal to divergent in front of flower, subequal, 17—27 mm long, white, glabrous; anthers exserted, versatile, dithecal, ± 4.5 mm long, pale yellow–orange, glabrous, longitudinally dehiscent; pollen whitish; nectary disc = a small swelling at tip of ovary next to style, weakly lobed, producing copious thin nectar fill corolla tube; pistil 1; ovary inferior, ± obovoid, 2.5 × 1.6 mm, green, without a neck, glabrous, 3–chambered, each chamber with several ovules; style long–exserted, relatively straight, slender, 45—60 × 0.35 mm long, white light yellow like filaments, narrow at base, expanded and greenish beneath stigma, glabrous; stigma exserted ca. 5 mm beyond anthers, terminal, ± hemispheric weakly 3–lobed, green, short–papillate.
Fruit berry, to 12–seeded, spheric, (5.5—)6—8 mm, blackish, glabrous except at top with cone–shaped calyx 0.3 mm land short–hairy on tips of lobes; pulp juicy, purple–red.
Seed slightly domed and like a turtle shell, broadly elliptic in outline, ca. 3 × 2 × 0.7 mm, brown and sometimes reddish dotted, ± cordlike on margin forming rim well–defined on ± concave side and weakly defined on convex side, central portion raised.
A. C. Gibson