CON VOL V ULA CEA I 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 game 

 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 Labiatae 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 1, entire, 2-cleft, or 2-parted; mostly twining 

 vines. 



Leaves normal. Fam. 1. Convolvulzceae. 



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



Fam. 2. Cuscntaceae. 

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

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



Fam. 4. Hydrophyllaceae. 

 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 Me?itha and Lycopus 

 of the Labiatae, and nearly or quite so in Verbena and Callicarpa of the Verbenaceae). 



I. Carpels 1-2-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 1-2-celled, 2-valved, circum- 



scissile, or irregularly bursting, not elastically dehiscent. 



Placenta? 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. Scrophulariaceae. 



Ovary 1 -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, or woody vines; capsule 2-celled: seeds winged in our genera. 



Fam. 12. Bf^noniaceae. 

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



Fam. 13. Martyniaceae. 

 X X Capsule completely 2-celled, elastically loculicidally dehiscent: opposite-leaved 

 herbs: placentae axile. Fam. 14. Acanthaceae 



3. Ovary and fruit i-celled with 1 erect orthotropous ovule and seed; herb with spicate 

 flowers and reflexed fruits. Fam. 15. Phrymaceae. 



Family 1. CONVOLVULACEAE Vent. 



Morning-glory Fa?nily. 



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, 5-lobed or 



