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



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



Fam. 32. Martyniaceae. 3 : 239. 



JJ Capsule completely 2-celled, elastically loculicidally dehiscent; opposite-leaved herbs; placentae 



axile. 



Fam. 33. Acanthaceae. 3 : 239. 



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



and reflexed fruits. 



Fam. 34. Phrymaceae. 3 : 244. 

 ** Corolla scarious, nerveless. 



Order 6. PLANTAGINALTES. 

 Herbs with small spicate or capitate flowers ; one family. Fam. 35. Plantaginaceae. 3 : 245. 



B. Ovary inferior. 



I. Anthers distinct. 



Stamens as many as the corolla-lobes and alternate with them (one fewer in Linnaea of the Capri- 

 foliaceae), or twice as many; ovary compound, with i ovule or more in each cavity; leaves 

 opposite, or verticillate. Order 7. RUBIALES. 



Stamens as many as the corolla-lobes. 



Leaves always stipulate, usually blackening in drying. Fam. 36. Rubiaceae. 3 : 250. 



Leaves usually exstipulate, not blackening in drying. Fam. 37. Caprifoliaceae. 3 : 267. 



Stamens twice as many as the corolla-lobes ; low herb with ternately divided leaves. 



Fam. 38. Adoxaceae. 3 : 283. 



Stamens mostly fewer than the corolla-lobes; ovary i -celled with i pendulous ovule, or 3-celled with 



2 of the cavities without ovules. Order 8. VALERIANALES (Aggregatae). 



Ovary 3-celled, 2 of its cavities empty. Fam. 39. Valerianaceac. 3 : 284. 



Ovary i-celled; flowers densely capitate, involucrate. Fam. 40. Dipsacaceae. 3:288. 



II. Anthers united (except in Campanula and Specularia of the Campanulaceae, in Ambrosiaceae, 

 and in Kuhnia of the compositae). Order 9. CAMPANULALES (Campanulatae) . 



Flowers not in involucrate heads; juice mostly milky. 



Endosperm none ; flowers monoecious or dioecious ; our species vines. 



Fam. 41. Cucurbit aceae. 3 

 Endosperm present, fleshy ; flowers perfect. 



Flowers regular. Fam. 42. Campanulaceae. 3 



Flowers irregular. Fam. 43. Lobeliaceac. 3 



Flowers in involucrate heads. 



Flowers all expanded into rays (ligulate) ; juice milky. Fam. 44. Cichoriaceae. 3 



Flowers all tubular, or the outer expanded into rays ; juice very rarely milky. 



Stamens distinct, or nearly so. Fam. 45. Ambrosiaceae. 3 



Stamens united by their anthers into a tube around the style (except in Kuhnia). 



Fam. 46. Compositae. 3 



290. 



293- 

 299. 



304. 

 338. 

 347- 



