XXII 
KEY TO THE ORDERS. 
Plants with tendrils; fruit a pepo; leaf-blades palmately 
veined. Cucurbitaceae in Order 47. Campanulales. 
II. Petals more or less united. 
Ovary superior. 
Stamens free from the corolla. 
Gynoecium of a single carpel. Families in Order 27. Rosales, 
Gynoecium of several united carpels. 
Filaments united. 
Stamens diadelphous. Fumariaceae in Order 26. Papaverales. 
Stamens monadelphous. 
Anther-sacs opening by slits. 
Oxalidaceae in Order 28. Geraniales. 
Anther-sacs opening by pores. 
Calyx and corolla very irregular. 
Order 29. Polygalales. 
Calyx and corolla regular. 
Families in Order 39. Ericales. 
Filaments distinct. Families in Order 39. Ericales. 
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 1-celled; placentae central or basal. 
Order 40. Primulales. 
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. 
Carpels united. 
Ovary 1-celled, with central placentae. 
Order 42. Gentianales. 
Ovary 2-3-celled, or falsely 4-celled, or if i-celled with 
parietal placentae. Order 44. Polemoniales. 
Corolla scarious, veinless; fruit a pyxis. 
Order 45. Plantaginales. 
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. 
Stamens 5 or fewer; anther-sacs opening by longitudinal slits. 
Order 47. Campanulales. 
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. 
Cucurbitaceae in Order 47. Campanulales. 
Plants not tendril-bearing. 
Ovules mostly on basal placentae ; plants parasitic. 
Order 22. Santalales. 
Ovules variously borne, but not on a basal placenta; plants not 
parasitic. Order 46. Rubiales. 
Ovary with one fertile cavity. 
Flowers not in heads, often in head-like spikes or racemes. 
Order 48. Valerianales. 
Flowers in involucrate heads. Order 49. Carduales. 
325 
169 
149 
220 
221 
258 
258 
261 
269 
264 
271 
320 
260 
325 
325 
100 
321 
326 
327 
