An Illustrated Flora of the Northern United States, Canada and the British Possessions/General Key to the Orders and Families

Class 2. .
Ovules enclosed in an ovary.

Subclass 2. Dicotyledones.
Embryo normally with 2 cotyledones; stems mostly differentiated into pith, wood and bark; leaves mostly net-veined.

Series 1. Choripetalae.
Petals distinct to the base, or wanting (exceptions noted)

Series 2. Gamopetalae.

 * Fam. 13. Oleaceae.
 * Fam. 13. Oleaceae.




 * b.||Stamens as many as the corolla-lobes; mostly herbs.
 * }
 * Stigmas distinct; juice not milky; ovary 1, compound.
 * Stigmas distinct; juice not milky; ovary 1, compound.
 * Stigmas distinct; juice not milky; ovary 1, compound.


 * Ovary 2-celled; leaves stipulate, or their bases connected by a stipular line.
 * Ovary 2-celled; leaves stipulate, or their bases connected by a stipular line.
 * Ovary 2-celled; leaves stipulate, or their bases connected by a stipular line.


 * Fam. 14. Loganiaceae.
 * Fam. 14. Loganiaceae.


 * Ovary 1-celled; celled; leaves not stipulate.
 * Ovary 1-celled; celled; leaves not stipulate.
 * Ovary 1-celled; celled; leaves not stipulate.


 * Leaves opposite or rarely verticillate; corolla-lobes convolute or imbricated in the bud.
 * Leaves opposite or rarely verticillate; corolla-lobes convolute or imbricated in the bud.
 * Leaves opposite or rarely verticillate; corolla-lobes convolute or imbricated in the bud.


 * Fam. 15. Gentianaceae.
 * Fam. 15. Gentianaceae.


 * Leaves basal or alternate ; corolla-lobes induplicate-valvate in the bud; marsh or aquatic herbs.
 * Leaves basal or alternate ; corolla-lobes induplicate-valvate in the bud; marsh or aquatic herbs.
 * Leaves basal or alternate ; corolla-lobes induplicate-valvate in the bud; marsh or aquatic herbs.


 * Fam. 16. Menyanthaceae.
 * Fam. 16. Menyanthaceae.


 * Stigmas united; juice milky; ovaries 2 in our species.
 * Stigmas united; juice milky; ovaries 2 in our species.
 * Stigmas united; juice milky; ovaries 2 in our species.


 * Styles united; stamens distinct; pollen of simple grains.
 * Styles united; stamens distinct; pollen of simple grains.
 * Styles united; stamens distinct; pollen of simple grains.


 * Fam. 17. Apocynaceae.
 * Fam. 17. Apocynaceae.


 * Styles distinct; stamens mostly monadelphous; pollen-grains united into waxy masses.
 * Styles distinct; stamens mostly monadelphous; pollen-grains united into waxy masses.
 * Styles distinct; stamens mostly monadelphous; pollen-grains united into waxy masses.


 * Fam. 18. Asclepiadaceae.
 * Fam. 18. Asclepiadaceae.


 * Ovary 1, compound (2-divided in Dichondra; in Boraginaceae and Labiatae mostly deeply 4-lobed around the style) flowers regular or irregular; stamens mostly adnate to the middle of the corolla-tube or beyond; leaves opposite or alternate.
 * Ovary 1, compound (2-divided in Dichondra; in Boraginaceae and Labiatae mostly deeply 4-lobed around the style) flowers regular or irregular; stamens mostly adnate to the middle of the corolla-tube or beyond; leaves opposite or alternate.
 * Ovary 1, compound (2-divided in Dichondra; in Boraginaceae and Labiatae mostly deeply 4-lobed around the style) flowers regular or irregular; stamens mostly adnate to the middle of the corolla-tube or beyond; leaves opposite or alternate.

Order 5. Polemoniales &emsp; &emsp; &emsp; (Tubiflorae).
 * a. Corolla regular (irregular in Echium of the Boraginaceae).
 * a. Corolla regular (irregular in Echium of the Boraginaceae).
 * a. Corolla regular (irregular in Echium of the Boraginaceae).


 * Ovary not 4-lobed, the carpels not separating as separate nutlets at maturity.
 * Ovary not 4-lobed, the carpels not separating as separate nutlets at maturity.
 * Ovary not 4-lobed, the carpels not separating as separate nutlets at maturity.


 * Ovary 2-divided.
 * Ovary 2-divided.
 * Ovary 2-divided.


 * Fam. 19. Dichondraceae.
 * Fam. 19. Dichondraceae.


 * Ovary 2-celled, rarely 3-4-celled; style 1, entire, 2-cleft, or 2-parted; mostly twining vines.
 * Ovary 2-celled, rarely 3-4-celled; style 1, entire, 2-cleft, or 2-parted; mostly twining vines.
 * Ovary 2-celled, rarely 3-4-celled; style 1, entire, 2-cleft, or 2-parted; mostly twining vines.


 * Leaves normal.
 * Leaves normal.
 * Leaves normal.


 * Fam. 20. Colvolvulaceae.
 * Fam. 20. Colvolvulaceae.


 * White or yellowish parasitic vines, the leaves reduced to minute scales.
 * White or yellowish parasitic vines, the leaves reduced to minute scales.
 * White or yellowish parasitic vines, the leaves reduced to minute scales.


 * Fam. 21. Cuscutaceae.
 * Fam. 21. Cuscutaceae.


 * Ovary 3-celled; stigmas 3, linear; herbs, not twining.
 * Ovary 3-celled; stigmas 3, linear; herbs, not twining.
 * Ovary 3-celled; stigmas 3, linear; herbs, not twining.


 * Fam. 22. Polemoniaceae.
 * Fam. 22. Polemoniaceae.


 * Ovary 1-celled (2-celled in Nama) ; style 1, 2-lobed, or 2-parted; herbs, not twining.
 * Ovary 1-celled (2-celled in Nama) ; style 1, 2-lobed, or 2-parted; herbs, not twining.
 * Ovary 1-celled (2-celled in Nama) ; style 1, 2-lobed, or 2-parted; herbs, not twining.


 * Fam. 23. Hydrophyllaceae.
 * Fam. 23. Hydrophyllaceae.


 * Ovary deeply 4-lobed around the style, or not lobed (Heliotropium); carpels separating as nutlets.
 * Ovary deeply 4-lobed around the style, or not lobed (Heliotropium); carpels separating as nutlets.
 * Ovary deeply 4-lobed around the style, or not lobed (Heliotropium); carpels separating as nutlets.


 * Fam. 24. Boraginaceae.
 * Fam. 24. Boraginaceae.




 * b.||Corolla irregular, more or less 2-lipped (regular in Solanaceae, in Mentha and Lycopus of the Labiatae, and nearly or quite so in Verbena and Callicarpa of the Verbenaceae).
 * }
 * 1. Carpels 1-2-seeded.
 * 1. Carpels 1-2-seeded.
 * 1. Carpels 1-2-seeded.


 * Ovary not lobed, 2-4-celled, the style apical; carpels separating into 1-seeded nutlets.
 * Ovary not lobed, 2-4-celled, the style apical; carpels separating into 1-seeded nutlets.
 * Ovary not lobed, 2-4-celled, the style apical; carpels separating into 1-seeded nutlets.


 * Fam. 25. Verbenaceae.
 * Fam. 25. Verbenaceae.


 * Ovary 4-lobed around the style, the lobes ripening into 1-seeded nutlets.
 * Ovary 4-lobed around the style, the lobes ripening into 1-seeded nutlets.
 * Ovary 4-lobed around the style, the lobes ripening into 1-seeded nutlets.


 * Fam. 26. Labiatae.
 * Fam. 26. Labiatae.


 * ||colspan="2"|
 * 2. Carpels several-many-seeded (2-seeded in some Acanthaceae).
 * 2. Carpels several-many-seeded (2-seeded in some Acanthaceae).


 * Fruit a berry, or more commonly 1 capsule which is 1-2-celled, 2-valved, circumscissile, or irregularly bursting, not elastically dehiscent.
 * Fruit a berry, or more commonly 1 capsule which is 1-2-celled, 2-valved, circumscissile, or irregularly bursting, not elastically dehiscent.
 * Fruit a berry, or more commonly 1 capsule which is 1-2-celled, 2-valved, circumscissile, or irregularly bursting, not elastically dehiscent.


 * Placentae axile.
 * Ovary 2-celled, or rarely 3~5-celled.
 * Placentae axile.
 * Ovary 2-celled, or rarely 3~5-celled.


 * Flowers regular; fertile stamens 5 (4 in Petunia); fruit a berry or capsule.
 * Flowers regular; fertile stamens 5 (4 in Petunia); fruit a berry or capsule.
 * Flowers regular; fertile stamens 5 (4 in Petunia); fruit a berry or capsule.


 * Fam. 27. Solanaceae.
 * Fam. 27. Solanaceae.


 * Flowers more or less irregular; fertile stamens 2 or 4 (5 in Verbascum); fruit a capsule.
 * Flowers more or less irregular; fertile stamens 2 or 4 (5 in Verbascum); fruit a capsule.
 * Flowers more or less irregular; fertile stamens 2 or 4 (5 in Verbascum); fruit a capsule.


 * Fam. 28. Scrophulariaceae.
 * Fam. 28. Scrophulariaceae.


 * Ovary 1-celled; marsh or aquatic herbs with flowers on scapes.
 * Ovary 1-celled; marsh or aquatic herbs with flowers on scapes.
 * Ovary 1-celled; marsh or aquatic herbs with flowers on scapes.


 * Fam. 29. Lentibulariaceae.
 * Fam. 29. Lentibulariaceae.


 * Placentae parietal.
 * Placentae parietal.
 * Placentae parietal.


 * Herbs, parasitic on the roots of other plants, the leaves reduced to scales, not green; ovary 1-celled.
 * Herbs, parasitic on the roots of other plants, the leaves reduced to scales, not green; ovary 1-celled.
 * Herbs, parasitic on the roots of other plants, the leaves reduced to scales, not green; ovary 1-celled.


 * Fam. 30. Orobanchaceae.
 * Fam. 30. Orobanchaceae.


 * Trees, vines, shrubs, or herbs, the foliage normal.
 * Trees, vines, shrubs, or herbs, the foliage normal.
 * Trees, vines, shrubs, or herbs, the foliage normal.


 * Trees, shrubs, or woody vines; capsule 2-celled; seeds winged in our genera.
 * Trees, shrubs, or woody vines; capsule 2-celled; seeds winged in our genera.
 * Trees, shrubs, or woody vines; capsule 2-celled; seeds winged in our genera.


 * Fam. 31. Bignoniaceae.
 * Fam. 31. Bignoniaceae.


 * Opposite-leaved herbs; capsule 1-celled in our genus; seeds wingless.
 * Opposite-leaved herbs; capsule 1-celled in our genus; seeds wingless.
 * Opposite-leaved herbs; capsule 1-celled in our genus; seeds wingless.


 * Fam. 32. Martyniaceae.
 * Fam. 32. Martyniaceae.


 * Capsule completely 2-celled, elastically loculicidally dehiscent; opposite-leaved herbs; placentae axile.
 * Capsule completely 2-celled, elastically loculicidally dehiscent; opposite-leaved herbs; placentae axile.
 * Capsule completely 2-celled, elastically loculicidally dehiscent; opposite-leaved herbs; placentae axile.


 * Fam. 33. Acanthaceae.
 * Fam. 33. Acanthaceae.




 * 3.||Ovary and fruit 1-celled with 1 erect orthotropous ovule and seed; herb with spicate flowers and reflexed fruits.
 * }
 * Fam. 34. Phrymaceae.
 * Fam. 34. Phrymaceae.

Order 6. Plantaginales.
 * Corolla scarious, nerveless.
 * Corolla scarious, nerveless.
 * Corolla scarious, nerveless.
 * Herbs with small spicate or capitate flowers ; one family.
 * Herbs with small spicate or capitate flowers ; one family.
 * Herbs with small spicate or capitate flowers ; one family.


 * Fam. 35. Plantaginaceae.
 * Fam. 35. Plantaginaceae.


 * }