Key to the Trees of New England
| I. LEAVES SIMPLE. | |
|---|---|
| Leaves alternate | A |
| Outline entire | A C |
| Outline slightly indented | A D |
| Outline lobed | A E |
| Lobes entire | A E F |
| Lobes slightly indented | A E G |
| Lobes coarsely toothed | A E H |
| Leaves opposite | B | |
|---|---|---|
| A C | Ovate to oval, obscurely toothed | Tupelo |
| A C | Ovate to oval | Persimmon |
| A C | Also 3-lobed | Sassafras |
| A C | Sometimes opposite, clustered at the ends of the branchlets | Dogwoods |
| A D | Tremulous habit, oval | Poplars |
| A D | Lanceolate, finely serrate, sometimes entire | Willows |
| A D | Ovate-oval, serrate, doubly serrate | Birches Hornbeams |
| A D | Oval, serrate, oblong-lanceolate, veins terminating in teeth | Beeches Chestnut |
| A D | Ovate-oblong, doubly serrate, surface rough | Elms |
| A D | Ovate to ovate-lanceolate, serrate, surface slightly rough | Hackberry |
| A D | Outline variable, ovate-oval, sometimes lobed (3-7), serrate-dentate | Mulberry |
| A D | Ovate, serrate, oblong | Shadbush Plums Cherries |
| A D | Oval or oval-oblong, spines, evergreen | Holly |
| A D | Broad-ovate, one-sided, serrate | Linden |
| A D | Obovate, oval, lanceolate, oblong | Chestnut oaks |
| A D | Broad-ovate to broad-elliptical, thorny | Thorns |
| A E F | Lobes rounded | Sassafras |
| A E F | Base truncate or heart-shaped | Tulip tree |
| A E F | Obtuse, rounded lobes | White oaks |
| A E F | 3-5-lobed, white-tomentose to glabrous beneath | White poplar |
| A E G | 5-lobed, finely serrate | Sweet gum |
| A E G | Irregularly 3-7-lobed, serrate-dentate with equal teeth | Mulberry |
| A E H | Pointed or bristle-tipped lobes | Black oaks |
| A E H | Coarse-toothed or pinnate-lobed, short lobes ending in sharp point | Sycamore |
| B | Outline entire, ovate, veins prominent | Flowering dogwood |
| B | Outline serrate, apex often tapering | Sheep berry |
| B | Outline lobed | Maples |
| II. LEAVES COMPOUND. | ||
|---|---|---|
| Leaves pinnately compound | I | |
| Leaflets alternate | I A | |
| Outlines of leaflets entire | I A C | |
| Leaflets opposite | I B | |
| Leaves bi-pinnately compound | J | |
| I A | Outlines of leaflets with two or three teeth at base. | Ailanthus |
| I | Outlines of leaflets serrate | Sumacs (except Poison sumac) Mountain ashes Walnuts Hickories |
| I A C | Leaflets oval, apex obtuse | Locusts (except Honey locust) |
| I A C | Leaflets oblong, apex acute | Poison sumac |
| I B | Outlines of leaflets entire | Ashes (except Mountain ashes) |
| I B | Outlines of leaflets serrate | Ashes (except Mountain ashes) |
| I B | Leaflets irregularly or coarsely toothed, 3-lobed or nearly entire | Box elder |
| J | Irregularly bi-pinnate, outlines of leaflets entire, thorns on stem and trunk | Honey locust |