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Lonicera
See list of 13 species in this genus-
1a. Flowers paired, borne on axillary peduncles [Figs. 546,548]; plants upright (twining or climbing in L. japonica); leaves all distinct
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2a. Plants twining or climbing; leaves persistent; corolla 30–50 mm long; fruit black
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2b. Plants upright; leaves deciduous; corolla 10–22 mm long; fruit red or blue
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3a. Style glabrous; corolla ± actinomorphic [Fig. 546]
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4a. Ovaries definitely united; fruit blue; corolla gibbous at the base on one side; bractlets subtending the flowers mostly 4–6 mm long; winter buds with 2 scales; plants mostly of hydric soils
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4b. Ovaries separate [Fig. 546]; fruit red; corolla with a short spur at the base; bractlets subtending the flowers mostly 1.2–3 mm long; winter buds with more than 2 scales; plants mostly of mesic soils
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3b. Style pubescent; corolla weakly to strongly zygomorphic [Fig. 548]
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5a. Branchlets with solid, white pith; bractlets subtending the flowers obsolete; plants native, of circumneutral fens
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5b. Branchlets with hollow, darker pith; bractlets subtending the flowers 2–8 mm long; plants introduced, of fields, roadsides, and disturbed areas
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6a. Peduncles shorter than 5 mm; leaf blades abruptly tapering to an acuminate apex
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6b. Peduncles 5–25 mm long [Fig. 548]; leaf blades obtuse to acute at the apex
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7a. Upper lip of the corolla with shallow sinuses, the sinuses extending ca. half the distance to the base of the lip; filaments pubescent; bractlets and ovary glandular; winter buds fusiform, the scales conspicuously ciliate
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7b. Upper lip of the corolla with deep sinuses, the sinuses extending nearly to the lip’s base [Fig. 548]; filaments glabrous or pubescent only near base; bractlets and ovary eglandular; winter buds conical or ovoid, ciliate or not
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8a. Leaf blades pubescent on the abaxial surface; peduncles 5–15 mm long; corolla white (turning yellow), pubescent on the abaxial (i.e., outside) surface, saccate at the base; branchlets pubescent [Fig. 548]
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8b. Leaf blades glabrous on the abaxial surface; peduncles 15–25 mm long; corolla usually pink to red (fading yellow), glabrous on the abaxial surface, not saccate at the base; branchlets glabrous
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1b. Flowers in 3-flowered cymules, sessile in the axils of leaves [Fig. 547]; plants twining or climbing; upper 1 or 2 pairs of leaves gamophyllous (all distinct in L. periclymenum)
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9a. Leaf blades pubescent on abaxial surface, green on adaxial surface
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9b. Leaf blades glabrous on abaxial surface, thinly to conspicuously glaucous on adaxial surface
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10a. All the leaves distinct, with petioles; basal connate tube of the corolla glandular-pubescent; distal end of the branchlets usually glandular-pubescent
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10b. Upper 1–4 pairs of leaves gamophyllous and lacking petioles [Fig. 547]; basal connate tube of the corolla eglandular; branchlets usually glabrous
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11a. Corolla 30–50 mm long, weakly zygomorphic, the 5 lobes nearly equal; seeds 4–4.5 mm long
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11b. Corolla 15–30 mm long, strongly zygomorphic, with an upper and lower lip; seeds either 3–3.5 mm long or 4.5–5 mm long
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12a. Uppermost gamophyllous leaf blades green adaxially, bluntly pointed to pointed at the apex, collectively forming a rhombic-elliptic to double-ovate disk [Fig. 547]; seeds 3–3.5 mm long
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12b. Uppermost gamophyllous leaf blades glaucous adaxially, rounded to retuse at the apex, collectively forming a suborbicular to orbicular disk; seeds 4.5–5 mm long
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Each photo represents one species in this genus.