T r e e s  o f  N o r t h  C a r o l i n a

Ilex L. (Aquifoliaceae)

A genus of 400-500 species of mostly trees and shrubs; cosmopolitan and widespread in tropical and temperate areas, especially Asia and America. The genus Nemopanthus is clearly best subsumed into Ilex.

Fourteen arborescent species occur in North Carolina. The shrubby I. glabra is not treated here.

Key to arborescent Ilex in North Carolina

1. Leaves coriaceous, evergreen…2.

2. Leaves with a well-developed apical spine (and usually also marginal spines) 2-6 mm long…3.

3. Flowers in 1-few-flowered axillary cymes, on growth of the same year; leaves somewhat yellowish green above, 3-12 cm long, 2.0-5.5 cm wide; [widespread in our area]…I. opaca (American holly)

3. Flowers in axillary clusters, on branches of the previous year; [alien shrub, rarely naturalized, especially in suburban areas]…*I. cornuta (Chinese holly, Burford holly)

2. Leaves with margins either entire, crenate, serrate, or with marginal spinose prickles < 1 mm long (the apex sometimes mucronate, but not stiff and spinose)…4.

4. Leaves crenate from base to apex, 0.5-4.5 cm long; calyx and corolla 4-lobed…I. vomitoria (Yaupon)

4. Leaves entire, crenate (if so, only beyond the midpoint), serrate, or with marginal spinose prickles, 2-10 cm long; calyx and corolla 4-lobed or 5-9-lobed; fruits red, yellow, or black…5.

5. Fruits black; calyx and corolla 5-9-lobed; leaves crenate near the tip or with a few marginal spinose prickles, or entire, with dark punctate dots beneath…I. coriacea (Big gallberry)

5. Fruits red or yellow; calyx and corolla 4-lobed; leaves entire (or with spinose serrations), lacking dark punctate dots beneath…6.

6. Leaves oblanceolate, oblong, or elliptic, 3-12 cm long, (8-) 15-40 mm wide, 2-4× as long as wide; petioles (3-) 5-15 mm long; leaf apex acute, obtuse, or rounded; branchlets strongly ascending, most of them forming an angle of < 45 degrees to the branch…I. cassine (Dahoon)

6. Leaves lanceolate to narrowly oblong, 2-4 cm long, 3-8 mm wide, 3-7× as long as wide; petioles 1-3 (-5) mm long; leaf apex acute to acuminate; branchlets ascending to spreading, most of them forming angles greater than 45 degrees to the branch, and often at right angles…I. myrtifolia (Myrtle holly)

1. Leaves membranous, deciduous, toothed…7.

7. Leaves oblanceolate or obovate, broadest above the middle, 8-30 (-45) mm wide, narrowly cuneate basally, mostly 2-3× as long as wide…8.

8. Pedicels of fruits and pistillate flowers 2-6 mm long; pedicels of staminate flowers (2-) 4-8 (-16) mm long; leaves mostly gray green, often revolute, especially toward the base; pubescence of the lower leaf surface tomentose, primarily on or near the midrib; leaf margins rarely ciliate…I. decidua (Possum-haw)

8. Pedicels of fruits and pistillate flowers (5.5-) 10-30 mm long; pedicels of staminate flowers (10-) 15-25 mm long; leaves rarely revolute; pubescence of the lower leaf surface strigose, distributed on the surface; leaf margins often ciliate…I. longipes (Georgia holly)

7. Leaves elliptic or ovate, broadest near the middle, (10-) 20-55 mm wide, rounded to broadly cuneate basally, mostly 1-2.5× as long as wide…9.

9. Veins on undersurface of leaf blades reticulate, defining areoles; fruit surface dull; fruiting pedicels 6-14 mm long (averaging about 10 mm); [of blackwater floodplains and clay-based Carolina bays of the Coastal Plain]…I. amelanchier (Sarvis holly)

9. Veins on undersurface of leaf blades obscure, not defining areoles; fruit surface shiny; fruiting pedicels either (8-) 10-30 mm long or 2-9 mm long (averaging either < 6 mm or > 15 mm long); [collectively of various habitats, widespread in our area]…10.

10. Fruiting pedicels (8-) 10-30 mm long; fruit (7-) 8-12 mm in diameter, bright cherry-red; [of bogs and very moist forests of the Mountains]…I. collina (Long-stalked holly)

10. Fruiting pedicels 2-9 mm long; fruit 5-9 (-12) mm in diameter, red to orange; [collectively of various habitats, widespread in our area]…11.

11. Nutlets (5-) 6-8 per fruit, smooth on the (curved) back; staminate flower clusters on peduncles 2-6 mm long; pistillate flowers with entire corolla lobes; flowers mostly in axils of leaves on normal shoots...12.

12. Sepals glabrous (in flower or fruit), acute; leaves lighter green, slightly if at all rugose...I. laevigata (Smooth winterberry)

12. Sepals ciliate (in flower or fruit), obtuse; leaves darker green, often moderately rugose...I. verticillata (Winterberry)

11. Nutlets 4-5 per fruit, with striate ridges on the (curved) back; staminate flower clusters sessile or very short-peduncled (0-2 mm long); pistillate flowers with ciliate corolla lobes; flowers mostly in axils of leaves on lateral short-shoots...13.

13. Leaves 2-9 (-10.5) cm long, elliptic to broadly ovate, often nearly round, the apex abruptly to gradually acuminate, the marginal teeth usually inconspicuous; petioles of mature leaves usually < 1 cm long; fruits 5-9 mm in diameter; plant a shrub to 6 m tall; [of the Mt, Pd, CP]…I. ambigua (Carolina holly)

13. Leaves 6-16 cm long (the largest, at least, > 8 cm long), narrowly to broadly ovate, the apex long acuminate to attenuate, the marginal teeth rather coarse; petioles of mature leaves usually > 1 cm long; fruits 9-12 mm in diameter; plant shrub or small tree to 10 m tall; [of the Mt and upper Pd]…I. montana (Mountain holly)