Ericaceae, the Heath Family
Herbs or shrubs, frequently with evergreen leaves; sepals 4-5; corolla regular, with 4-5 petals; stamens as many or twice as many; ovary 3-10-celled, with 1 style.
| 1a. Plants without green color; leafless or with scale leaves only — 2. | |
| 1b. Plants with green leaves — 4. | |
| 2a. Flowers solitary (1-2 dm. high; summer) | Indian Pipe, Monotropa uniflora. |
| 2b. Flowers in clusters — 3. | |
| 3a. Petals united into a bell-shape corolla (3-9 dm. high; summer) | Pine Drops, Pterospora andromedea. |
| 3b. Petals all separate (1-3 dm. high; summer) | Beech Drops, Monotropa hypopitys. |
| 4a. Leaves all basal; herbaceous plants with terminal racemes (1-4 dm. high; summer) (Shin-leaf) — 5. | |
| 4b. Stem-leaves present — 12. | |
| 5a. Style straight — 6. | |
| 5b. Style bent near the apex — 8. | |
| 6a. Racemes one-sided, the flowers all turned in one direction (flowers white or greenish-white) — 7. | |
| 6b. Raceme regular, the flowers not all pointing in the same direction (flowers white or pink) | Shin-leaf, Pyrola minor. |
| 7a. Flowers numerous in each raceme | Shin-leaf, Pyrola secunda. |
| 7b. Flowers only 3-7 in each raceme | Shin-leaf, Pyrola seconda var. obtusata. |
| 8a. Flowers pink or purple — 9. | |
| 8b. Flowers white or greenish — 10. | |
| 9a. Leaves cordate at base | Shin-leaf, Pyrola asarifolia. |
| 9b. Leaves rounded at base, not cordate | Shin-leaf, Pyrola asarifolia var. incarnata. |
| 10a. Leaves shining on the upper side; sepals one-third as long as the petals | Shin-leaf, Pyrola americana. |
| 10b. Leaves dull on the upper side; sepals one-fourth as long as the petals, or a little shorter — 11. | |
| 11a. Leaf-blades mostly shorter than their petioles, thick and firm | Shin-leaf, Pyrola chlorantha. |
| 11b. Leaf-blades thin, usually longer than their petioles | Shin-leaf, Pyrola elliptica. |
| 12a. Petals nearly or quite separate from each other — 13. | |
| 12b. Petals united into a gamopetalous corolla, the tube of which is as long as or longer than the lobes — 18. | |
| 13a. Leaves opposite or whorled; stems herbaceous or nearly so (summer) — 14. | |
| 13b. Leaves alternate; stems shrubby (early summer) — 16. | |
| 14a. Flowers solitary; leaves broadly ovate to nearly circular (1 dm. high; flower white) | One-flowered Wintergreen, Moneses uniflora. |
| 14b. Flowers in clusters; leaves narrow (stems trailing, 1-3 dm. high; flowers white or pinkish) — 15. | |
| 15a. Leaves broadest above the middle, green | Prince’s Pine, Chimaphila umbellata. |
| 15b. Leaves broadest below the middle, spotted with white | Spotted Wintergreen, Chimaphila maculata. |
| 16a. Leaves 2-5 cm. long, densely woolly beneath (5-10 dm. high; flowers white) | Labrador Tea, Ledum groenlandicum. |
| 16b. Leaves 1-2 cm. long, pale beneath but not wholly (creeping; flowers pink) (Cranberry) — 17. | |
| 17a. Leaves acute | Cranberry, Vaccinium oxycoccos. |
| 17b. Leaves obtuse | Cranberry, Vaccinium macrocarpon. |
| 18a. Leaves opposite or whorled; corolla saucer-shape (shrubs 3-8 dm. high; flowers purple, summer) — 19. | |
| 18b. Leaves alternate; corolla bell-shape or salver-form — 20. | |
| 19a. Branches and twigs cylindrical, not angled | Sheep Laurel, Kalmia angustifolia. |
| 19b. Branches and twigs with 2 sharp angles | Swamp Laurel, Kalmia polifolia. |
| 20a. Plants prostrate, or with a few ascending branches only (flowers white or pink) — 21. | |
| 20b. Plants erect or ascending — 23. | |
| 21a. Flowers 10-20 mm. long, very fragrant (early spring) | Trailing Arbutus, Epigaea repens. |
| 21b. Flowers 4-5 mm. long (late spring) — 22. | |
| 22a. Leaves spatulate, broadest beyond the middle | Bearberry, Arctostaphylos uva-ursi. |
| 22b. Leaves oval, broadest at the middle | Snowberry, Chiogenes hispidula. |
| 23a. Leaves linear, white beneath, their margins strongly revolute (shrub 3-8 dm. high; flowers white, late spring) | Bog Rosemary, Andromeda glaucophylla. |
| 23b. Leaves oblong, scurfy beneath with rusty scales (bog shrub 4-10 dm. high; flowers white, in spring) | Leatherleaf, Chamaedaphne calyculata. |
| 23c. Leaves smooth, pubescent, or resinous beneath, but not scurfy nor white — 24. | |
| 24a. Low shrubs 10-15 cm. high, erect from a creeping rootstock; leaves with the taste of wintergreen (flowers white or pink, summer) | Wintergreen, Gaultheria procumbens. |
| 24b. Bushy shrubs 3-8 dm. high; leaves dotted beneath with yellowish resinous dots; ovary 10-celled (flowers greenish-pink, spring) | Huckleberry, Gaylussacia baccata. |
| 24c. Shrubs 1 dm. to 3 m. high; leaves not resinous-dotted beneath; ovary 5-celled (flowers white or greenish-pink, spring or early summer) — 25. | |
| 25a. Corolla bell-shape, the stamens projecting beyond it (5-15 dm. high) | Deerberry, Vaccinium stamineum. |
| 25b. Corolla cylindrical or urn-shape, the stamens not projecting — 26. | |
| 26a. Filaments hairy (Blueberry) — 27. | |
| 26b. Filaments glabrous (Bilberry) — 32. | |
| 27a. Low bushy shrubs, usually less than 5 dm. and never more than 1 m. high — 28. | |
| 27b. Tall erect shrubs, 1-4 m. high — 31. | |
| 28a. Foliage pubescent | Blueberry, Vaccinium canadense. |
| 28b. Foliage glabrous — 29. | |
| 29a. Leaves pale-green and glaucous, entire or nearly so | Blueberry, Vaccinium vacillans. |
| 29b. Leaves bright-green, distinctly serrulate — 30. | |
| 30a. Fruit blue | Blueberry, Vaccinium pennsylvanicum. |
| 30b. Fruit black | Blueberry, Vaccinium pennsylvanicum var. nigrum. |
| 31a. Leaves downy beneath; fruit black | Blueberry, Vaccinium atrococcum. |
| 31b. Leaves smooth or minutely pubescent beneath; fruit blue | Blueberry, Vaccinium corymbosum. |
| 32a. Full-grown leaves less than 2.5 cm. long; low much-branched shrubs, mostly less than 5 dm. high — 33. | |
| 32b. Full-grown leaves more than 2.5 cm. long; shrubs usually a meter high or more — 34. | |
| 33a. Leaves entire; petals usually 4. | Bilberry, Vaccinium uliginosum. |
| 33b. Leaves finely serrulate; petals 5 | Bilberry, Vaccinium caespitosum. |
| 34a. Leaves serrulate, green beneath, acute; corolla globular | Bilberry, Vaccinium membranaceum. |
| 34b. Leaves entire, pale beneath, obtuse; corolla ovoid | Bilberry, Vaccinium ovalifolium. |