tt 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 (Tubiflorae).

a. Corolla regular (irregular in Echium of the Boraginaceae).

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

Ovary 2-divided. Fam. 19. Dichondraceae. 3: 39.

Ovary 2-celled, rarely 3-4-celled; style 1, entire, 2-cleft, or 2-parted; mostly twining vines. Leaves normal. Fam. 20. Colvolvulaceae. 3: 40.

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

Fam. 21. Cuscutaceae. 3:48. Ovary 3-celled; stigmas 3, linear; herbs, not twining. Fam. 22 Polemoniaceae. 3: 52.

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

Fam. 23. Hydrophyllaceae. 3: 65. Ovary deeply 4-lobed around the style, or not lobed (Heliotropium); carpels separating as nutlets.

Fam. 24. Boraginaceae. 3: 72.

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.

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

Fam. 25. Verbenaceae. 3:94. Ovary 4-lobed around the style, the lobes ripening into i-seeded nutlets. Fam. 26. Labiatae. 3: 99.

2. Carpels several-many-seeded (2-seeded in some Acanthaceae).

| Fruit a berry, or more commonly * 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.

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

Fam. 27. Solanaceae. 3: 154. Flowers more or less irregular; fertile stamens 2 or 4 (5 in Verbascum); fruit a capsule.

Fam. 28. Scrophulariaceae. 3:172. Ovary 1-celled; marsh or aquatic herbs with flowers on scapes.

Fam. 29. Lentibulariaceae. 3: 225. Placentae parietal.

Herbs, parasitic on the roots of other plants, the leaves reduced to scales, not green; ovary i-celled. Fam. 30. Orobanchaceae. 3:233.

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

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

Fam. 31. Bignoniaceae. 3:236.

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

Fam. 32. Martyniaceae. 3: 239.

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

Fam. 33. Acanthaceae. 3: 239. 3. Ovary and fruit i-celled with 1 erect orthotropous ovule and seed; herb with spicate flowers and reflexed fruits.

Fam. 34. Phrymaceae. 3: 244. ** Corolla scarious, nerveless.

Order 6. Plantaginales. Herbs with small spicate or capitate flowers; one family. Fam. 35. Plantaginaceae. 3: 245.

B. Ovary inferior.

I. Anthers distinct.

Stamens as many as the corolla-lobes and alternate with them (one fewer in Linnaea of the Capri-foliaceae), or twice as many; ovary compound, with 1 ovule or more in each cavity; leaves opposite, or verticillate. Order 7. Rubiales.

Stamens as many as the corolla-lobes.

Leaves always stipulate, usually blackening in drying. Fam. 36. Rubiaceae. 3: 250.

Leaves usually exstipulate, not blackening in drying. Fam. 37. Caprifoliaceae. 3: 267.

Stamens twice as many as the corolla-lobes; low herb with ternately divided leaves.

Fam. 38. Adoxaceae. 3:283.

Stamens mostly fewer than the corolla-lobes; ovary 1-celled with 1 pendulous ovule, or 3-celled with 2 of the cavities without ovules. Order 8. Valerianales (Aggregatae).

Ovary 3-celled, 2 of its cavities empty. Fam. 39. Valerianaceae. 3: 284.

Ovary i-celled; flowers densely capitate, involucrate. Fam. 40. Dipsacaceae. 3:288.

II. Anthers united (except in Campanula and Specularia of the Campanulaceae, in Ambrosiaceae, and in Kuhnia of the compositae). Order 9. Campanulales (Campanulatae).

Flowers not in involucrate heads; juice mostly milky.

Endosperm none; flowers monoecious or dioecious; our species vines.

Fam. 41. Cucurbitaceae. 3:290. Endosperm present, fleshy; flowers perfect.

Flowers regular. Fam..42. Campanulaceae. 3:293.

Flowers irregular. Fam. 43. Lobeliaceae. 3: 299.

Flowers in involucrate heads.

Flowers all expanded into rays (ligulate); juice milky. Fam. 44. Cichoriaceae. 3: 304.

Flowers all tubular, or the outer expanded into rays; juice very rarely milky.

Stamens distinct, or nearly so. Fam. 45. Ambrosiaceae. 3: 338.

Stamens united by their anthers into a tube around the style (except in Kuhnia).

Fam. 46. Compositae. 3: 347.