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Vaccinium
See list of 13 species in this genusThere are herbarium specimens from various locations in New England that have been referred to as hybrids. These include, for example, collections of Vaccinium angustifolium with entire leaves (considered to be V. angustifolium ×V. myrtilloides; specimens at VT!) and V. angustifolium with glaucous leaves (considered to be V. angustifolium ×V. uliginosum; specimens at VT!). Some of these determinations are doubtful, others are difficult to confirm. More work, including field and herbarium research, is needed to verify the authenticity of these putative hybrids. Reference: Vander Kloet (1988).
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1a. Leaf blades coriaceous, lustrous, evergreen; shrubs prostrate or trailing, up to 2 dm tall; corolla with 4 lobes [Fig. 621]; fruit usually red or dark red, tart at maturity
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2a. Corolla divided to near the middle; leaf blades with erect, black glands on the abaxial surface; pedicels less than 5 mm long
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2b. Corolla divided to below the middle [Fig. 621]; leaf blades without glands on the abaxial surface; pedicels 10–50 mm long
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3a. Leaf blades elliptic-oblong, rounded at the apex, with flat or slightly revolute margins; pedicels with green, leaf-like bracteoles 2–4 ×1–2 mm [Fig. 621]; styles 5–7 mm long; berry 10–15 mm in diameter
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3b. Leaf blades ovate to triangular, acute at the apex, with strongly revolute margins; pedicels with red, scale-like bracteoles 0.5–2 × less than 1 mm; styles 3–4 mm long; berry 6–12 mm in diameter
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1b. Leaf blades herbaceous, not lustrous, deciduous; shrubs prostrate or upright, never trailing, 0.5–30 dm tall; corolla with 4 or, more commonly, 5 lobes [Figs. 622,623]; fruit blue to blue-black, sweet at maturity
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4a. Branchlets not papillose; anthers with a pair of upward-projecting awns in addition to the terminal tubules
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5a. Corolla scutelliform to open-campanulate [Fig. 623], open in bud; stamens exserted; berry (7–) 10–14 (–18) mm in diameter
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5b. Corolla urceolate [Fig. 622], closed in bud; stamens included within the corolla; berry 5–9 mm in diameter
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6a. Flowers 5-merous; winter buds with 2 scales; leaf blades finely serrulate; calyx continuous with the pedicel
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6b. Flowers mostly 4-merous; winter buds with more than 2 scales; leaf blades entire; calyx articulated with the pedicel
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4b. Branchlets papillose; anthers lacking awns
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7a. Crown-forming, single- to several-stemmed shrubs 1–3 (–4) m high; mature leaf blades (30–) 38–80 mm long; corolla (4–) 5–10 mm long
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8a. Leaf blades darkening in drying, moderately to densely pubescent abaxially with brown-gray to brown hairs; berry black, not glaucous; winter bud scales brown-green to black; branchlets pubescent throughout circumference; flowers precocious
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8b. Leaf blades not darkening in drying, glabrous or sparsely pubescent abaxially with white to gray-white hairs; berry blue to dark blue, glaucous; winter bud scales pink to red; branchlets glabrous, pubescent in 2 lines, or infrequently pubescent throughout circumference; flowers coetaneous
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9a. Leaf blades 30–50 mm long, 15–20 mm wide, eciliate, glaucous abaxially, entire; corolla 4–6 mm long; berry 5–8 mm in diameter
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9b. Leaf blades (30–) 38–80 mm long, 20–30 mm wide, ciliate, green or glaucous abaxially, entire or serrulate; corolla 5–10 mm long; berry 6–12 mm in diameter
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7b. Rhizomatous, colonial, many-stemmed shrubs 0.01–1 (–1.15) m tall; leaf blades 8–45 (–50) mm long; corolla 3–8 mm long
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10a. Leaf blades entire or nearly so [Fig. 622]
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11a. Branchlets and leaf blades evidently pubescent; winter bud scale apex acute; leaf blades not glaucous, elliptic to narrow-elliptic
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11b. Branchlets and leaves sparsely pubescent at most; winter bud scale apex rounded; leaf blades glaucous, ovate to broad-elliptic (in part)
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10b. Leaf blades finely serrulate
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12a. Leaf blades 8–21 ×2–6 mm, narrow-elliptic (rarely elliptic); plants rarely reaching 9 cm tall; corolla 3–4 mm long; berries 3–5 mm in diameter
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12b. Leaf blades (10–) 15–50 ×6–22 mm, narrow-elliptic to broad-elliptic or ovate; plants 9–51 cm tall; corolla 4–8 mm long; berries (3–) 4–9 (–12) mm in diameter
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13a. Leaf blades regularly serrulate, glaucous or, more commonly, not glaucous, (10–) 15–32 (–41) mm long, ca. ⅓ as wide, elliptic to, less commonly, narrow-elliptic
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13b. Leaf blades often irregularly serrulate, glaucous, (15–) 30–50 mm long, ca. ½ as wide, broad-elliptic to ovate [Fig. 622] (in part)
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Each photo represents one species in this genus.