CON voLruLA CEA E. 749 



obscurely toothed ; in their sinuses a pair of very slender linear-subulate teeth of 

 more than double their length, much surpassing the stigma. Mo. and Ark. to Ga. 

 May-June. 



Order 5. POLEMONIALES. 



Mostly herbs ; rarely shrubs or trees. Corolla almost always gamo- 

 petalous, regular or irregular. Stamens adnate to the corolla-tube usu- 

 ally to the middle or beyond, as many as the corolla-lobes, or fewer and 

 alternate with them. Ovary i, superior, compound (in Boraginaceae 

 and Labiatse deeply 4-lobed around the style). 



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

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



Ovary 2-celled, rarely 3~4-celled; style i, entire, 2-cleft, or 2-parted; mostly twining 

 vines. 



Leaves normal. Fam. i. Convolvulaceae. 



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



Fam. 2. Cuscutaceae. 



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

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



Fam. 4. HydropJiyllaceae. 



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

 as nutlets. Fam. 5. 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 Verbenaand. 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. 6. Verbenaceae. 

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



Fam. 7. Labiatae. 



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



% Fruit a berry, or more commonly a capsule which is i-2-celIed, 2-valved, circum- 

 scissile, 6r 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. 8. Solanaceae. 



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

 capsule. Fam. 9. Scrophulariaccae. 



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



Fam. 10. Lentibulariaceae. 

 Placentas parietal. 



Herbs, parasitic on the roots of other plants, the leaves reduced to scales, not green ; 

 ovary i-celled. Fam. n. Orobanchaceae. 



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



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



Fam. 12. Bignoniaceae. 

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



Fam. 13. Martyniaceae. 

 J 1 Capsule completely 2-celled, elastically loculicidally dehiscent; opposite-leaved 



herbs; placentae axile. Fam. 14. Acanthaceae 



3. Ovary and fruit i-celled with i erect orthotropous ovule and seed; herb with spicate 

 flowers and reflexed fruits. Fam. 15. Phrymaceae. 



Family i. CONVOLVULACEAE Vent. 

 Morning-glory Family. 



Herbs or vines, some tropical species shrubs or trees, with alternate 

 estipulate leaves, and regular perfect axillary cymose or solitary flowers. 

 Calyx inferior, 5-parted or 5-divided, usually persistent, the segments or 

 sepals imbricated. Corolla gamopetalous, the limb 5-angled, s-lobed or 



