i -> ^ KEY TO THE ORDERS. 



Ovules several in each cavity. PAGE 



Ovary with parietal placentae. 



Loasaceae in Order OPUNTIALES. 808 

 Ovary with central or basal placentae. 



Families in Order MYRTALES. 822 

 Ovary exceeding the hypanthium, the top free. 



Hydrangeaceae in Order ROSALES. 494 

 Plants with tendrils. 



Herbs: fruit a pepo: leaf-blades palmately veined. 



Cucurbitaceae in Order CAMPANULALES. 1134 

 Shrubby vines: fruit drupaceous, separating into nutlets: leaf-blades 



pinnately veined. Rhamnaceae in Order RHAMNALES. 747 



** Petals more or less united. 

 Ovary superior. 



Stamens free from the corolla. 



Gynoecium of a single carpel. Families in Order ROSALES. 494 



Gynqecium of several united carpels. 

 Filaments united. 



Stamens diadelphous. Fumariaceae in Order PAPAVERALES. 460 



Stamens monadelphous. 



Anther-sacs opening by slits. Oxalidaceae in Order GERANIALES. 658 



Anther-sacs opening by pores. 



Calyx and corolla very irregular. Order POLYGALALES. 682 



Calyx and corolla regular. Families in Order ERICALES. 876 



Filaments distinct. 



Styles wanting or very short: stigma sessile. 



Aquifoliaceae in Order SAPINDALES. 723 

 Styles elongated. 



Ovary several-celled. Families in Order ERICALES. 876 



Ovary 1-celled. Armeriaceae in Order PRIMULALES. 898 



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 PRIMULALES. 898 



Placentae parietal. Fouquieriaceae in Order HYPERICALES. 781 



Ovary several-celled. 



Upper portion of the ovaries distinct. Sedaceae in Order ROSALES. 494 



Upper portion of the ovaries united. Order EBENALES. 908 



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. 

 Gynoecium of 3-6 carpels. 



Shrubs or trees: ovules and seeds few. Aquifoliaceae in Order SAPINDALES. 723 

 Herbs, or creeping or tufted shrubby plants: ovules and seeds numerous. 

 Stamens adnate up to the sinuses of the corolla: creeping evergreen under- 



shrubs. Diapensiaceae in Order ERICALES. 876 



Stamens adnate to the lower part of the corolla-tube: vines. 



Families in Order POLEMONIALES. 956 

 Gynoecium of 2 carpels. 



Carpels distinct, except sometimes at the apex. 



Style terminal Order ASCLE^ADALES. 933 



Style basal. Dichondraceae in Order POLEMONIALES. 956 



Carpels united. 



Ovary 1-celled, with central placentae. Order GENTIANALES. 921 



Ovary 2-celled, or falsely 4-celled, or if 1-celled with parietal placentae. 



Stamens 2 and opposite each other, or 3. Order OLEALES. 916 



Stamens usually 4 or 5, if 2 by reduction not opposite each other. 

 Leaves with stipules or stipular lines at their bases. 



Spigeliaceae in Order GENTIANALES. 921 



Leaves with no traces of stipules. Order POLEMONIALES. 956 



Corolla scarious, veinless: fruit a pyxis. Order PLANTAGINALES. 1097 



Ovary inferior. 



Stamens with the filaments free from the corolla. 



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



Vacciniaceae in Order ERICALES. 876 



Stamens 5 or fewer: anther-sacs opening by longitudinal slits. Order CAMPANULALES. 1134 

 Stamens adnate to the corolla. 



Ovary with 2-many fertile cavities and 2-many ovules: calyx unmodified, at least not 



a pappus. 



Plants tendril-bearing. Cucurbitaceae in Order CAMPANULALES. 1134 



Plants not tendril-bearing. 



Ovules mostly on basal placentae: plants parasitic. Order SANTALALES. 1101 



Ovules variously borne, but not on a basal placenta: plants not parasitic. 



Order RUBIALES. 1104 

 Ovary with one fertile cavity. 



Ovules numerous on a basal placenta. Primulaceae in Order PRIMULALES. 898 



Ovule solitary, the placentae not basal. 



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



Order VALERIANALES. 1127 

 Flowers in involucrate heads. Order CARDUALES. 1148 



