25. Haloragaceous plants - herbs; leaves whorled; flowers minute, the calyx four-lobed or wanting; stamens 8-6-4, or sometimes reduced to one; fruit dry, containing a solitary seed.

26. Cornaceous plants - shrubs; leaves opposite; calyx-teeth petals and stamens four each; fruit 1-2-celled, the cells containing a solitary seed.

†† Flowers in umbels.

27. Umbelliferous plants - herbs; leaves alternate; fruit dry, of two carpels adhering by their face (commissure) to a common central axis; seed solitary.

Monopetals: Dichlamydeous plants, with the petals united (from the base more or less upwards) into a single piece; Orders 28 to 52.

* Stamens epigynous; (ovary inferior).

† Stamens attached to the corolla, the filaments cohering in three parcels.

28. Cucurbitaceous plants - herbs; leaves lobed; flowers unisexual, the calyx and corolla each five-parted; fruit succulent.

† † Stamens attached to the corolla, separate, alternating with its lobes; (ovules mostly solitary).

‡ Fruit three- to five-celled.

29. Caprifoliaceous plants - shrubs or herbs; leaves opposite; corolla five- rarely four-lobed, regular or irregular; fruit-cells one- or few-seeded.

‡‡ Fruit double, formed of two united one-seeded carpels.

30. Galiaceous plants - herbs; leaves and leaf-like stipules whorled around the four-angled stems; corolla four-lobed.

‡‡‡ Fruit single or one-seeded.

31. Valerianaceous plants - herbs; flowers not in close heads; corolla five-lobed; stamens fewer than the corolla-lobes.

32. Dipsacaceous plants - herbs; flowers in compact heads or spikes; stamens equalling in number the divisions of the four- or five-lobed corolla.

††† Stamens attached to the corolla, cohering by their anthers.

33. Composite plants - herbs; florets collected in heads; stamens as many as the corolla lobes; fruit dry, one-seeded.

††† Stamens free from the corolla, the anthers cohering.

Si. Lobeliaceous plants - herbs; flowers not in heads; stamens as many as the lobes of the corolla; fruit many-seeded.

†††† Stamens free from the corolla, the anthers distinct.

35. Campanulaceous plants - herbs; stamens as many as the lobes of the corolla; anthers opening longitudinally.

36. Vacciniaceous plants - shrubs; stamens twice as many as the lobes of the corolla; anthers opening by two terminal pores.

** Stamens hypogynous.

37. Ericaeeous plants - shrubs; stamens equal to or twice as many as the lobes of the corolla; anthers with an appendage, opening by two pores.

*** Stamens perigynous; (ovary superior). † Seeds attached to a free central placenta. ‡ Stamens opposite the corolla-lobes.

38. Primulaceous plants - herbs; stamens equalling in number the lobes of the corolla; style one; ovary many-seeded.

39. Plumbaginaceous plants - herbs; stamens equalling in number the lobes of the corolla; styles five; ovary containing one ovule, which is pendulous from the point of a thread (umbilical cord) rising from the base of the cavity.

‡‡ Stamens alternating with the corolla-lobes.

40. Plantaginaceous plants - herbs; stamens equalling in number the lobes of the four-cleft regular corolla; style one; ovary 1-2-celled, with one or several ovules.

41. Lentibulariaceous plants - herbs; corolla irregular, two lipped; stamens two, fewer than the corolla-lobes; ovary 1-celled, many-seeded.

†† Seeds attached to the sides of the cells (placentas 'parietal), or in their axial angle.

‡ Corolla regular or nearly so.

§ Ovary entire (not lobed), its cells with one or two ovules.

42. Aquifoliaceous plants - trees or shrubs; corolla 4-6-parted; stamens as many, alternating with its lobes; fruit fleshy, 4-celled, with one ovule in each cell.

43. Oleaceous plants - trees or shrubs; corolla 4-parted or wanting, with two stamens alternating with its lobes; ovary two-celled, the cells two-seeded.

44. Convolvnlaceous plants - herbs; corolla plaited, 4-5-lobed, with as many alternating stamens; ovary 2-3-celled, the cells two- (rarely one-) seeded.

§§ Ovary entire (not lobed), its cells containing many seeds.

45. Polemoniaceous plants - herbs; corolla five-lobed, with as many alternating stamens; ovary three-celled. 40. Gentianaceous plants - herbs; corolla usually five-lobed (sometimes 4, 6. 8 or 10) with as many alternating stamens, twisted; ovary 1-2-celled.

47. Solanaceous plants - herbs; corolla five, rarely four-lobed, with as many alternating stamens, plaited; ovary two-celled.

§§§ Ovary four-lobed.

48. Boraginaceous plants - herbs; corolla five, rarely four-lobed, with as many alternating stamens; ovary four-celled, with a single ovule in each cell affixed at the base of the cavity.

‡‡ Corollas irregular. § Ovary four-lobed.

49. Labiate plants - herbs; corolla two-lipped; stamens usually four didynamous (2 long, 2 short), or sometimes only two; lobes of the ovary one-seeded.

§§ Ovary undivided (i.e.not lobed).

50. Verbenaceous plants - herbs; stamens four didynamous, rarely two; ovary four-celled, dividing when mature into four one-seeded nuts.

51. Scrophulariaceous plants - herbs; stamens four, didynamous; ovary two-celled, the cells many-seeded; placentas axile.

52. Orobanchaceous plants - leafless parasitical herbs; stamens four, didynamous; ovary one-celled, with two or more many-seeded parietal placentas.

Monochlamyds: Perianth single (i. e. consisting of a calyx only), or altogether wanting, and replaced by scaly bracts; Orders 53 to 59.

* Carpels solitary, simple. † Calyx inferior.

53. Chenopodiaceous plants - herbs; leaves without stipules; perianth small, the stamens (4-5, rarely 1-2), alternating with its lobes; ovule 1-celled, with one ovule.

54. Ceratophyllaceous plants - aquatic floating herbs; leaves without stipules; perianth none; ovary and fruit 1- seeded, or 4-lobed, with one seed in each lobe.

55. Urticaceous plants - herbs; leaves with distinct stipules; flowers unisexual; perianth small, green, the stamens, usually 4, opposite its segments; styles two, rarely one.

56. Polygonaceous plants - herbs; leaves with ochreate or sheathing stipules; perianth small; styles two or more.

†† Calyx superior.

57. Santalaceous plants - herbs; perianth with four or five small valvate lobes, and with four or five stamens opposite its lobes; styles simple; ovules 2-3; seed solitary.

** Carpels combined, two- or more-celled. † Calyx inferior.

58. Euphorbiaceous plants - herbs or shrubs; flowers unisexual; fruit consisting of three carpels, each containing one or two pendulous seeds.

†† Calyx superior.

59. Aristoloehiaceous plants - herbs; perianth irregular or three-lobed; stamens 12; ovary 3-6-celled, the cells many-seeded.