Group 3: Leaf scars alternate, pith homogenous

1. Prickles or thorns present...2.

2. Stems arching or trailing, longitudinally grooved; bundle scars not evident...Rubus spp.

2’. Stems erect, not grooved; bundle scars evident...3.

3. Bundle scars > 8; leaf scar deeply U-shaped and large...Aralia spinosa

3’. Bundle scars 3; leaf scar crescent-shaped, narrow...4.

4. Prickles lacking; at least some branch stems modified as thorns; stems often forming dense thickets...Prunus angustifolia

4’. Prickles present; branch stems not modified as thorns; stems not forming dense thickets...5.

5. Plant of dry soil; prickles straight to slightly curved...Rosa carolina

5'. Plant of wet or inundated soil; prickles curved...Rosa palustris

1’. Prickles and thorns lacking...6.

6. Stipular scar completely encircling stem...7.

7. Buds valvate...Liriodendron tulipifera

7’. Buds capitate...8.

8. Buds gray – black; leaf scar does not encircle axillary bud...Magnolia tripetala

8'. Buds brown; leaf scar encircles axillary bud...Platanus occidentalis

6’. Stipular scar lacking or present but not encircling stem...9.

9. Buds associated with different leaf scars clustered at twig ends (superposed buds of a single leaf scar near twig end do not constitute clustered buds)...10.

10. Bud scales brown or grayish–brown; plant a tree...Quercus spp.

10'. Bud scales tan, beige, pink, pink-tipped; plant a shrub...Rhododendron periclymenoides

9’. Buds associated with different leaf scars not clustered at twig ends...11.

11. Buds stalked...12.

12. Plants of wet or inundated soil; buds smooth or with dark brown hairs...Alnus serrulata

12'. Plants of dry soil; buds densely covered with short, tan, matted hairs...Hamamelis virginiana

11’. Buds sessile...13.

13. Buds naked or so densely hairy that scales cannot be seen...14.

14. Leaf scar deeply horseshoe-shaped...15.

15. Twigs round; leaf scars 2-ranked, not nearly surrounding buds...Asimina triloba

15'. Twigs 3-sided; leaf scars >2-ranked, nearly surrounding buds...Rhus glabra

14’. Leaf scar round, half-round, shield-shaped, or crescent-shaped...16.

16. Leaf scar round or nearly so...Rhus aromatica

16’. Leaf scar half-round, shield-shaped, or crescent-shaped...17.

17. Axillary buds often superposed, thumb-shaped; vascular bundle one, often elevated above surrounding leaf scar...Styrax grandifolius

17’. Axillary buds solitary, not thumb-shaped; vascular bundles >1, not elevated above surrounding leaf scar...18.

18. True terminal bud absent; false terminal present or absent...Rhus copallinum

18'. True terminal bud present...Toxicodendron radicans

13’. Buds obviously scaly (this lead includes buds with a single scale)...19.

19. Bud scale 1, capitate...Salix nigra

19’. Bud scales >1, imbricate or valvate...20.

20. Crushed twigs or scratched twig bark with distinct smell...21.

21. Smell spicy or otherwise pleasant...22.

22. Vascular bundle scars > 5, scattered in three groups; twigs stout...Carya

22'. Vascular bundle scars 1 or 3; twigs fine to moderately stout...23.

23. Vascular bundle scars 3; axillary buds >1 in and slightly above some leaf axils...Lindera benzoin

23'. Vascular bundle scar single, straight, elongate transverse band; axillary bud single...Sassafras albidum

21'. Smell unpleasant, not spicy

24. Vascular bundle scar 1; buds < 2 mm long, sunken into stem tissue; twigs frequently reddish...Oxydendrum arboreum

24'. Vascular bundle scars 3; buds 2-3 mm long, distinct, not sunken into stem tissue; twigs grayish or brown...Prunus serotina

20’. Crushed twigs or scratched twig bark lacking distinct smell...25.

25. [moved left] Bundle scar 1 per leaf scar...26.

26. Short, spur shoots with closely spaced leaf scars present; stipular scars present (may be difficult to see without handlens)...Ilex decidua

26’. Spur shoots lacking; stipular scars not evident...27.

27. Axillary buds often superposed...Ilex verticillata

27’. Axillary buds solitary...28.

28. Buds partly sunken in stem tissue; twig bark maroon...Oxydendrum arboreum

28’. Buds not sunken; twig bark brown, black, gray, green or pink...29.

29. Bud scales acute, acuminate or apiculate; twig bark green or pink...30.

30. Leaf bud scales acute or apiculate but not acuminate; young twigs not warty dotted...Vaccinium stamineum

30’. Leaf bud scales acuminate; young twigs warty dotted...31.

31. Shrub to 3 m tall...Vaccinium corymbosum s.l.

31'. Low shrub, 30-50 cm tall...Vaccinium pallidum

29’. Bud scales acute or obtuse; twig bark brown, gray, maroon, pink, or green...32.

32. Bundle scar a straight, horizontal, elongated band...Sassafras albidum

32’. Bundle scar curved or oval (not straight and elongated)...33.

33. Bud scales green, brown, or pink, with golden glands...Gaylussacia frondosa

33’. Bud scales brown-black, lacking glands...34.

34. Bud scales 2, overlapping with a wavy line, dark brown-black; older twigs not striate; plant a tree...Diospyros virginiana

34’. Bud scales several, imbricate, reddish-brown; older twigs distinctly striate; plant a shrub...Eubotrys racemosa [=Leucothoe racemosa]

25’. Bundle scars >1 per leaf scar...35.

35. Wood (internal to bark) conspicuously yellow...Xanthorhiza simplicissima

35’. Wood (internal to bark) brown, gray, tan, pinkish, or white...36.

36. Leaf scar edge slightly elevated as a rim, interior sunken-dished; vascular bundle scars slightly elevated...Morus rubra

36’. Leaf scar edge not elevated, interior not sunken; bundle scars not elevated...37.

37. Axillary bud recurved toward twig...Amelanchier arborea

37’. Axillary bud straight, not recurved...38.

38. Axillary bud length > 5X width...Fagus grandifolia

38’. Axillary bud length < 5X width...39.

39. Each bundle scar a white ring with a dark center...Liquidambar styraciflua

39’. Bundle scars not as above...40.

40. Bundle scars > 5, scattered or in 3 groups...Carya spp.

40’. Bundle scars < 5...41.

41. Buds often slightly to one side of leaf scar; bundle scars slightly depressed into leaf scar tissue...42.

42. Some twigs have corky wings...Ulmus alata

42’. Twigs lack corky wings...43.

43. Buds smooth-slightly hairy; twigs smooth-slightly hairy...Ulmus americana

43'. Buds densely hairy; twigs rough hairy...Ulmus rubra

41’. Buds usually centered above leaf scar; bundle scars not depressed...44.

44. Vegetative bud scales 4 or fewer...45.

45. Scales of axillary leaf buds 2-3, buds often superposed...Cercis canadensis

45’. Scales of axillary leaf buds 3-4, buds solitary...46.

46. Bud oblong or narrowly lanceolate, ratio of bud length / greatest width > 2; twigs reddish-brown...Betula nigra

46’. Bud deltate, ratio of bud length / greatest width < 2; twigs greenish-brown or gray...Celtis laevigata

44’. Vegetative bud scales > 4...47.

47. Bud apex obtuse; twig ends with short, protruding, stiffish, reddish-brown hairs...Corylus americana

47’. Bud apex acute; twig ends smooth or with hairs not as above...48.

48. Bud scales not striate or, if striate, then not distinctly...Carpinus caroliniana

48'. Bud scales distinctly longitudinally striate...Ostrya virginiana

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Last updated Jan 2012