xxii KEY TO THE ORDERS. 



riaiils with tendrils ; fruit a pepo ; leaf-blades palmatcly 

 veined. Cucurhitacex in Order 47. Cami'anulales. 325 



II. Petals more or less united. 

 Ovary superior. 



Stamens free from the corolla. 



Gyna-cium of a single carpel. Families in Order 2"]. Rosales. 169 



Gyna'ciuni of several united carpels. 

 Filaments united. 



Stamens diadelphous. Fumariaceae in Order 2(>. Papaverales. 149 

 Stamens monadelphous. 



Anther-sacs opening by slits. 



Oxalidacex in Order 28. Geraniales. 220 

 Anther-sacs opening by pores. 

 Calyx and corolla very irregular. 



Order 29. Polvgalales. 221 

 Calyx and corolla regular. 



Families in Order 39. Ericales. 258 

 Filaments distinct. Families in Order 39. Ericales. 258 



Stamens partially adnate to the corolla. 



Stamens as many as the lobes of the corolla and opposite them, or 

 twice as many or more; ovary i-celled; placenta: central or basal. 



Order 40. Primulales. 261 

 Stamens as many as the lobes of the corolla and alternate with 

 them, or fewer. 

 Corolla not scarious, veiny ; fruit various, but not a pyxis. 

 Carpels distinct, except sometimes at the apex. 



Order 43. Asclepiadales. 269 

 Carpels united. 



Ovary i -celled, with central placentae. 



Order 42. Ge.ntia.nales. 264 

 Ovary 2-3-celled, or falsely 4-celled, or if i -celled with 

 parietal placentje. Order 44. Polemoniales. 271 



Corolla scarious, veinless ; fruit a pyxis. 



Order 45. Plantaginales. 320 

 Ovary inferior. 



Stamens with the filaments free from the corolla. 



Stamens 10; anther-sacs opening by terminal pores or chinks. 



Vacciniaceae in Order 39. Ericales. 260 

 Stamens 5 or fewer ; anther-sacs opening by longitudinal slits. 



Order 47. Campanulales. 325 

 Stamens adnate to the corolla. 



Ovary with 2-many fertile cavities and 2-many ovules ; calyx un- 

 modified, at least not a pappus. 

 Plants tendril-bearing. 



Cucurbitacea; in Order 47. Campanulales. 325 

 Plants not tendril-bearing. 



Ovules mostly on basal placentae ; plants parasitic. 



Order 22. Saxtalales. 100 

 Ovules variously borne, but not on a basal placenta ; plants not 

 parasitic. Order 46. Rubiales. 321 



Ovary with one fertile cavity. 



Flowers not in heads, often in head-like spikes or racemes. 



Order 48. Valerianales. 326 

 Flowers in involucrate heads. Order 49. Carduales. 327 



