2008 Symposium Handout
Identification of Native Eastern U.S. Viburnums
by Ron Lance
| <--------- Using Summer Foliage | Using Fall/Winter Twigs ------> | ||
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leaf petioles hairy, non-glandular | V. acerifolia (1) -- twigs sometimes hairy; terminal buds with 2 to 4 pairs of brownish scales |
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| leaf petioles hairless, with red glands | V. trilobum (2) -- twigs hairless; terminal buds with 1 pair of valvate reddish scales, seam often obscure | ||
| Leaves Lobed | Terminal Buds Scaled; Coarse Shrubs often < 2 m Tall | ||
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leaves >10 cm broad, veiny, finely toothed | V. lantanoides (3) -- terminal buds naked, > 1cm long |
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| leaves <5 cm long, obovate, nearly entire, petiole very short | V. obovatum (4) -- terminal buds naked or valvate, < 5 mm | ||
| Leaves of Unusual Size/Shape | Terminal Buds Naked or < 5 mm | ||
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leaves glossy, margin hairy, usually entire; flower/fruit cluster peduncles > 2 cm | V. nudum (5) -- terminal buds > 1 cm, brownish, lateral buds often short; flower buds incompletely valvate |
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| leaves dull, margin partly toothed, hairless; flower/fruit cluster peduncles < 2 cm | V. cassinoides (6) -- terminal buds > 1 cm, brownish, lateral buds udually elongate; flower buds incompletely valvate | ||
| leaves dull, margin sharply toothed, petioles wavy-margined | V. lentago (7) -- terminal buds > 1 cm, pinkish; flower buds completely valvate with 2 scales | ||
| leaves glossy, margin finely toothed, tip blunt | V. rufidulum (8) -- terminal buds < 1 cm, rusty-colored | ||
| leaves dull, margin finely toothed, tip acute | V. prunifolium (9) -- terminal buds < 1 cm, grayish | ||
| Leaves Elongate, Veins Branch Well Before Marginal Teeth | Terminal Buds Valvate-Scaled, Scurfy | ||
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leaves hairy, base mostly rounded to flat | V. dentatum (10) -- twigs hairy; fruit globose |
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| leaves hairless, base mostly rounded to flat | V. recognitum (11) -- twigs hairless; fruit globose | ||
| petioles < 1 cm, stipules persist; base various; leaf teeth < 12 per side | V. rafinesquianum (12) -- twigs hairless; terminal buds often narrow-based, some scales grayish; fruit elliptical | ||
| leaf base usually cordate, stipules persist; petiole > 1 cm, red-glandular hairy | V. molle (13) -- stem bark shreddy; bud scales dark, usually keeled; fruit eliptical | ||
| leaf base usually cordate, stipules persist; petiole > 1 cm, no red glandular hairs | V. bracteatum (14) -- stem bark tight; bud scales dark; fruit eliptical | ||
| Leaves Wide Near Base, Strong Veins Extend to Large Teeth | Terminal Buds Imbricate-Scaled |