xxviu GENERAL KEY TO THE ORDERS AND FAMILIES. VOL. I. 



Stamens borne at the sinuses of the corolla, or united in a lo-lobed tube. 



Fam. 6. Diapensiaceae. 



II. Stamens borne on the corolla, as many as its lobes and opposite them, or twice as many, or more. 

 Herbs. Order 2. PRIMULALES. 



Style i ; fruit a capsule. Fam. 7. Primulaceae. 2 



Styles 5 ; fruit an achene or utricle. Fam. 8. Plumbaginaceae. 2 



Shrubs or trees. Order 3. EBENALES. 



Stamens as many as the corolla-lobes. Fam. 9. Sapotaceae. 2 

 Stamens twice as many as the corolla-lobes, or more. 



Styles 2-8; flowers mostly monoecious or dioecious. Fam. 10. Ebenaceae. 2 



70S- 



707. 

 717. 



719. 

 720. 



Style i, simple or lobed ; flowers mostly perfect. 



Stamens in several series. Fam. u. Symplocaceae. 2 711. 



Stamens in i series. Fam. 12. Styracaceae. 2 711. 



III. Stamens borne on the corolla, as many as its lobes or fewer, and alternate with them (in our 

 species of Fraxinus and Forestiera of the Oleaceae there is no corolla). 



* Corolla not scarious, nerved. 



t Ovaries 2, distinct (except in some Loganiaceae, and in Gentianaceae and Menyanthaceae, in which 



the ovary is compound, with 2 cavities, or rarely more, or with i cavity and 2 



placentae) ; flowers regular ; stamens mostly adnate to only the 



lower part of the corolla ; leaves mostly opposite. 



Order 4. GENTIANALES (Contortae). 



a. Stamens (usually 2), fewer than the corolla-lobes, or corolla none; our species 



trees or shrubs. 



Fam. 13. Oleaceae. 2: 723. 



b. Stamens as many as the corolla-lobes ; mostly herbs. 

 Stigmas distinct ; juice not milky ; ovary i, compound. 



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



Fam. 14. Loganiaceae. 2:729. 

 Ovary i-celled; leaves not stipulate. 



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



Fam. 15. Gentianaceae. 3: i. 



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

 herbs. Fam. 16. Menyanthaceae. 3:17. 



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



Styles united; stamens distinct; pollen of simple grains. Fam. 17. Apocynaceae. 3: 19. 



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



Fam. 1 8. Asclepiadaceae. 3: 23. 



tt Ovary i, 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. 



Orders. 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 i, 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 i, 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). 



i. Carpels i-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). 



J Fruit a berry, or more commonly i capsule which is i-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 : 1 72. 

 Ovary i -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. 



