GROUP K
Leaves simple, alternate, deciduous, more than 2-ranked, toothed and/or lobed.
KEY TO GENERA
1. Dormant end bud a terminal one (check on vigorous twigs) ...................... 2
2. Terminal bud without scales (naked), consisting of 2-3(4) erect miniature leaves of different sizes and densely covered with ascending woolly hairs …………………..Frangula
2. Terminal bud scales 2-many ................................................. 3
3. Terminal bud scales many, bundle scars in leaf scars many and scattered ................................................................ Quercus
3. Terminal bud scales mostly 2-6(to 10 in Exochorda) or lacking, bundle scars in leaf scars 1 or 3 ....................................... 4
4. Main leaf at all nodes a spine (some usually minute), in axil of each a stubby twig bearing 1 to many broad foliage leaves ........ Berberis
4. Main leaves with broad and flat blade, not a spine; stubby twigs absent or scant ............................................................ 5
5. Leaf scars with 1 prominently protruding bundle scar ... Clethra
5. Leaf scars with 3 or more bundle scars, or 1 and not protruding (slightly in some Ilex) .......................................... 6
6. Stipules present, borne on upper edges of petiole for as much as 8 mm, the free portion linear or uncommonly triangular to ovate, 0.5-1.7 mm; fruits pomes with seeds in a limber to firm-walled cavity .......................................................Photinia
6. Stipules absent or present only on twig, if present sometimes falling early but leaving a scar, this possibly minute; fruits otherwise or, if pomes, seeds enclosed in a bony-walled cavity .............................................................. 7
7. Leaf scars with 1 bundle scar ........................ 8
8. Stipules and their scars absent ................... Spiraea
8. Stipules and/or their scars present, sometimes on twig, sometimes on petiole, scarce on some species …….Ilex
7. Leaf scars with (2)3 bundle scars .................... 9
9. Leaves with odor of bay candles when crushed ...... 10
10. Vegetative axillary buds with 2-3(5) pairs of brown to light maroon scales; vascular trace in petiole a crescent ................................. Myrica
10. Vegetative axillary bud with 2 tan valvate scales which soon separate exposing other scales; vascular trace in petiole a thick ca 95° V-shaped bar ......................................... Morella
9. Leaves lacking such an odor ....................... 11
11. Twigs bearing thorns in leaf axils (sometimes scarce) ........................... Crataegus
11. Twigs unarmed ............................... 12
12. Twigs zigzag, a prominent thin ridge beginning at each corner of petiole base and 1 below it (See GROUP G) ........ Physocarpus
12. Twigs straight to curved, without thin ridges ........................ 11. Exochorda
1. Dormant end bud an axillary one (rarely a pair) at apex of vigorous twigs, or well below apex due to poorly developed apical portion or winter die-back . 1313. Vigorous twigs with all or at least a pair of leaves opposite (See GROUP E) .................................................................. ... Rhamnus
13. Vigorous twigs with alternate leaves ..................................... 14
14. Plants armed with spines or thorns (sometimes scarce) ..................15
15. Plants armed with spines (modified main leaves); leaves with a broad blade borne on a short axillary twig stub above each spine..... Berberis
15. Plants armed with thorns (sharp-pointed twigs), these with 11 bundle scars, leaf blade ovate (See GROUP E) .......................................................... Sageretia
14. Plants unarmed ....................................................... 16
16. Buds with only one scale, this fused into a cap or with free overlapping margins on side toward twig; most lateral year 1 twigs breaking off easily .............................................................. Salix
16. Buds with 2-many scales visible; lateral year 1 twigs usually breaking off with some difficulty ........................................... 17
17. Leaf blade oblong to narrowly elliptic, margin conspicuously lobed, lobes 12-43 on each edge and uniformly cut nearly to midvein ............................................ Comptonia
17. Leaf blade of other shapes or, if lobed, not evenly lobed ... 18
18. Lateral veins of leaf blade prominently parallel to each other or nearly so until near margin where some to most run parallel to margin and become quite small ....... Rhamnus
18. Lateral veins of leaf blade lacking all or most of these features ................................................. 19
19. An outer bud scale of axillary buds with back to twig................................................. Alnus
19. Outer bud scale(s) with edge to twig ................. 20
20. Leaf black with resinous glands, aromatic when bruised; stipules absent…21
21. Buds parallel with twig, scales 2 and edges fused ............................................. Lyonia
21. Buds angled with twig from a little to much, scales usually 3 or more and overlapping (2 and fused when young in Morella) .................................. 22
22. Vegetative axillary buds with 2-3(4) pairs of brown to light maroon scales; vascular trace in petiole a crescent ................................. Myrica
22.Vegetative axillary buds with 2 valvate scales that soon separate and expose other scales; vascular trace in petiole a thick ca 95° V-shaped bar ......................................... Morella
20. Leaf blade lacking resinous glands, not aromatic when bruised or, if having these characteristics, teeth numerous ........................................... 23
23. Leaf scars with (2)3 or more bundle scars; stipules and/or their scars present ...................... 24
24. Lateral veins of leaf blades 9-11 pairs .................................. Kerria
24. Lateral veins of leaf blades (6)7-8 pairs ................................ Neviusia
23. Leaf scars with 1 bundle scar; stipules and their scars absent or uncommonly present .............. 25
25. Leaf blade margin crenate or crenate-serrate, teeth 1-3 per cm .... Zenobia
25. Leaf blade margin serrate, occasionally some crenate-serrate, teeth usually more than 3 per cm, or some twigs with some or all leaves entire .................. 26
26. Vascular trace at mid-petiole 1/3 circular with a thick U-shaped mass of white soft cells adjacent to the sides and base of trace ....... Leucothoe
26. Vascular trace at mid-petiole crescent and lacking a mass of adjacent cells as described above ........................................................ 27
27. Leaf blade toothed or most or all entire; carpels separate… Spiraea
27. Leaf blade toothed; carpels united ...................... Vaccinium