xii GENERAL KEY TO THE POLYPETALOUS ORDERS. 



++ ++ Anthers 2(-3)-celled. 



27. STERCULIACExE. Flowers regular, mostly perfect. Petals sometimes want- 

 iuo'. Fertile stamens in N. American genera only as many as and alternate with 

 the sepals or calyx-lobes, in foreign genera often oc. Ovary (in ours) 5- or rarely 

 1-locular; ovules ascending or horizontal. Leaves alternate. 



28. TILIACE^. Flowers regular, mostly perfect. Stamens cc, quite free or slightly 

 united at the base into 5 phalanges ; anthers 2-celled. Ovules mostly pendulous 

 and with rhaphe ventral. Sepals deciduous. Leaves (in ours) alternate, simple, 

 serrate, dentate, or palmately lobed. 



* * DisciFLOR^. Stamens free from the calyx and ovary, variously inserted 

 upon a more or less expanded or developed torus, mostly definite, being of 

 the same number as the petals, or twice as many, or less frequently (through 

 partial suppression of one or both cycles) of some other number ; filaments 

 free or slightly monadelphous at the base or rarely (as in Meliacece) united 

 into a tube: torus commonly more or less developed into a disk-formed, 

 cup-shaped, annular, crenate, angled, or lobed fleshy or often glandular ex- 

 pansion or pulvinus, but not rarely obscure or undeveloped {Linacece, Ilex, 

 many species of Poly gala, &c.) : carpels 2 to 5 or rarely more numerous, 

 more or less united; ovary l-5(-oc)-celled, superior, surrounded by the 

 disk, or I'arely half inferior ; ovules anatropous or nearly so : sepals or calyx- 

 lobes mostly imbricated, rarely valvate in bud, mostly 4 or 5 : petals usu- 

 ally of the same number, inserted at the base of the calyx or upon the disk. 

 (N. B. Expanded disks or their glandular equivalents occur also in a few 

 ThalamiJiorcB, notably in Tamariscinece, Reseddcece, Pceonia, and some 

 Capparidacece.) 



-1— Geraniales. Ovules 1 to 2 (rarely x) in each cell, with few exceptions 

 horizontal or pendulous (in Rhus pendulous from the recurved apex of an 

 erect basilar funiculus) and with the rhaphe ventral, i. e. turned downward 

 and toward the axis of the ovary : disk mostly small (in Linacece represented 

 only by the glands of the receptacle, in Geraniacece often inconspicuous), 

 annular or lobed. 



++ Filaments free nearly or quite to the base. 



= Herbs with simple mostly alternate entire impunctate leaves : calyx (some- 

 times with marginal but) without dorsal glands. 



29. LINACEiE. Flowers regular, perfect, dichlamydeous ; envelopes (4-) 5-merous. 

 Fertile stamens in ours 5, slightly monadelphous at the base and with as many 

 minute interposed rudiments. Glands of the receptacle small, opposite the sepals. 

 Carpels and styles 2 to 5 ; cells of the ovary as many or by the intrusion of false 

 septa twice as many. Fruit in ours capsular ; seeds oily, with scanty albumen, 

 straightish embryo, and flat cotyledons. 



= = Woody-stemmed : calyx-lobes or sepals (except in Gnlphimia) bearing 

 one or two dorsal glands : leaves (in ours) opposite, simple, entire, 

 impunctate. 



30. IMALPIGHTACEjE. Flowers regular, 5-merous, 5-10-androus, in ours perfect 



