25. Apocynaceous Plants. Apocynaceae

(64) Vinca - corolla hypocrateriform, with a cylindrical tube, and flat spreading limb of oblique segments.

26. Gentianaceous Plants. Gentianaceae:

* Terrestrial plants with opposite leaves.

(65) Gentiana - calyx not divided below the middle; stamens five; style two-lobed, persistent.

** Aquatic plants, with alternate leaves. (66) Menyanthes - leaves trifoliolate; corolla fringed within.

27. Boraginaceous Plants. Boraginaceae

* Corolla without scales at the mouth of the tube.

(67) Pulmonaria - calyx tubular, the lobes not reaching to the middle; stamens included in the tube of the funnel-shaped corolla.

** Corolla having the mouth of the tube more or less closed by subulate scales.

(68) Symphytum - corolla tubular-campanulate, with five small teeth ; filaments entire.

28. Scrophulariaceous Plants. Scrophulariaceae

(69) Scrophularia - corolla small, nearly globular, with five unequal lobes; stamens four, often with rudiment of a fifth.

29. Orobanchaceous Plants. Orobanchaceae

(70) Lathraea - calyx bell-shaped, with four broad short teeth: upper lip of the corolla helmet-shaped.

30. Labiate Plants. Labiatae

* Two upper stamens longer than the two lower.

(71) Nepeta - calyx tubular, fifteen-ribbed; upper lip of the longtubed corolla straight, notched.

** Two upper stamens shorter than or only equaling to the lower. † Corolla distinctly two-lipped.

(72) Lamium - calyx regularly five-lobed; stamens longer than the corolla-tube.

†† Corolla apparently one-lipped.

(73) Ajuga - upper lip of corolla minute, tooth-like, entire or notched.

31. Thymelaceous Plants. Thymelaceae

(74) Daphne - perianth four-cleft, often coloured; stamens eight.

32. Ulmaceous Plants. Ulmaceae

(75) Ulmus - perianth bell-shaped, with four to six short lobes, and as many stamens.

33. Aristolochiaceous Plants. Aristolochiaceae

(76) Asarum - perianth bell-shaped, regular, three-cleft; stamens twelve.

34. Elaeagnaceous Plants. Elaegnaceae

(77) Hippophae - perianth of male flowers with two small segments and four stamens, of the females tubular, minutely two-lobed.

35. Euphorbiaceous Plants. Euphorbiaceae

(78) Buxus - perianth small, of four segments, in the male flowers with four stamens, in the females with three styles.

36. Empetraceous Plants. Empetraceae

(79) Empetrum - perianth of six scales, in two rows, with external imbricating similar bracts, the males with three stamens, the females with six or more radiating stigmas on a very short style.

37. Amentaceous Plants. Amentaceae

* Scales of the male catkins broad, imbricated; anthers longer than their filaments.

† Male and female catkins short, sessile, erect.

(So) Myrica - male catkins with spreading concave shining scales, the female ones shorter, with long protruding styles.

† †Male catkins cylindrical, usually pendulous.

(81) Alnus - flowers three distinct with four stamens under each scale of male catkins; female catkins small, ovoid.

(82) Betula - no distinct flowers; stamens six to twelve under each scale; female catkins short, cylindrical.

** Scales of the male catkins narrow-linear or divided; anthers small, on slender filaments.

(83) Salix - male and female catkins cylindrical, compact, the scales entire; stamens two, rarely three to five, with one or two gland-like inner scales.

(84) Populus - male and female catkins cylindrical, compact, the scales jagged; stamens several, within an oblique cup-shaped inner scale.