GENERAL KEY TO THE ORDERS. 13t 



PAGE 



Insectivorous plants, secreting a viscid liquid, with basal leaves and scaposc 



flowers. Order 17. SARRACENIALES. 469 



Carpels solitary, or several and distinct, or sometimes united; stamens mostly 

 perigynous or epigynous; sepals mainly united or confluent with the concave 



receptacle (hypanthium). Order 18. RQSALES. . 471 



Carpels united into a compound ovary; sepals mostly distinct (united more or 

 less in some Rhamnaceae). 



Stamens few, rarely more than twice as many as the petals. 



Stamens as many as the sepals or fewer and opposite them, or more 

 numerous. 



Ovules pendulous, the raphe toward the axis of the ovary. 



Order 19. GERANIALES 573 



Ovules pendulous, the raphe away from tie axis of the ovary, or 



erect, or ascending. Order 20. SAPINDALES 597 



Stamens as many as the sepals and alternate with them, opposite the 

 petals when these are present; ovules erect. 



Order 21. RHAMNALES. . . . 611 



Stamens usually very numerous (except in some Hypericaceae, in Elati- 

 naceae, Violaceae and Passifloraceae); disc inconspicuous, or none. 



Sepals valvate; placentas united in the axis of the capsule. 



Order 22. MALVALES 616 



Sepals or calyx-segments imbricated or convolute (except in Loasa- 

 ceae, in which the calyx-tube is adnate to the ovary; placentae 

 mainly parietal, sometimes united in the axis. 



Order 23. PARIETALES 623 



B Ovary inferior, adnate to the calyx, U'holly or in part (except in Lythraceae and 

 our Melastotnaceae, where it is usually merely enclosed by it, and in Thymeleaceae 

 and Elaeagnaceae, which are shrubs or trees with no corolla). 



Fleshy spiny plants, with jointed stems, the leaves very small or none in our 

 genera; calyx-segments and petals very numerous. 



Order 24. OPUNTIALES 642 



Herbs, shrubs or trees, not fleshy nor spiny; calyx-segments rarely more than 5. 



Petals none in our species; ovary i-ovuled. Order 25. THYMELEALES... 645 

 -Petals present (except in some Haloragidaceae, small aquatic herbs). 



Ovules several or numerous in each cavity of the ovary (except in Halo- 

 ragidaceae and Trapaceae, aquatic herbs). 



Order 26. MYRTALES 647 



Ovule i in each cavity of the ovary. Order 27. UMBELLALES 667 



ft PETALS MORE OR LESS UNITED (nearly or quite separate in Clethraceae, 

 Pyrolaceae. some Ericaceae, Primulaceae, Styracaceae, Asclepiadaceae, 

 Oleaceae, Cucurbitaceae and Galax of the Diapensiaceae). 



Series 2. Gamopetalae... 691 



\ Ovary superior (except in Vacciniaceae and Symplocaceae, in which it is 

 partly or wholly inferior). 



Stamens mostly free from the corolla, or adnate merely to its base (at the sinuses of 

 the corolla in Diapensia and Pyxidanthera of the Diapesiaceae), as many as the 



lobes and alternate with them, or twice as many. Order i. ERICALES 691 



Stamens borne on the corolla, as many as its lobes and opposite them, or twice as 

 many, or more. 



Herbs. Order 2. PRIMULALES... . 713 



Shrubs or trees. Or.Jer 3. EBENALES 720 



Stamens borne on the corolla, as many as its lobes or fewer, and alternate with 

 them (in our species of Fraxinus and Adelia of the Oleaceae there is no corolla). 

 Corolla not scarious, nerved. 



Ovaries 2, distinct (except in some Loganiaceae, and in Gentianaceae and 

 Menyanthaceae, in which the ovary is compound with 2 cavities or rarely 

 more, or with i cavity and 2 placenta? ; flowers regular ; stamens mostly 

 adnate to only the lower part of the corolla ; leaves mostly opposite. 



Order 4. GENTIANALES... 723 



Ovary i, compound (2-divided in Dichondra of the Convolvulaceae ; in 

 Boraginaceae and Labiatae mostly deeply 4-lobed around the style): flow- 

 ers regular or irregular; stamens mostly adnate to the middle of the co- 

 rolla-tube or beyond; leaves opposite or alternate. 



Order 5. POLEMONIALES.. 749 

 Corolla scarious, nerveless. Order 6. PLANTAGINALES. 856 



