70 MR. J, o. bakek's systema ieidaceaeum. 



Bounds of the Order, — Unlike the LiliacesD and Amaryllidacere, 

 IridacesD is one of the most strictly limited of natural orders. 

 The only genus about which there can be any doubt as to whether 

 it should be included in the order or not is Campynema^ which has 

 an inferior ovary, six stamens with extrorse anthers, melauthoid 

 leaves, and a tuft of fleshy root-fibres. It was placed by Brown in 

 Melanthaceee, by Mueller in Ilypoxidacese, but in Mr. Bentham's 

 view is better regarded as an anomalous Irid. 



Geographical Distribution. — As I am giving a table showing ^ 



the distribution of each genus, it is not needful to say much on 

 this head. The great concentration of the order is at this Cape, 

 where we get 312 out of 698 species. Out of G5 genera, 25 are 

 exclusively Cape and 7 are mainly Cape plants, but are feebly 

 represented in Tropical Africa. Of the three great subdivisions 

 of the order, the Gladiole^e are confined to the Old World, the 

 other two common to both the Old and the New. Although 

 Europe comes next to the Cape in number of species, it has only 

 one endemic genus {IIermodacti/lus),SiJid all its other species belong 

 either to Crocus and Xiphion (which it shares with Temperate Asia), 

 to Iris (which has the widest dispersion of any genus of the order), 

 or to Gladiolus^ Bomulea^ and Mor<ea (which it shares with the Cape 

 and Tropical Africa). The 56 Tropical- African species are out- 

 wandering representatives of the great Cape genera. Australia 

 has two endemic genera {Patersonia and Diplarrhena), a single 

 Iris^ and Orthrosanthus and Lihertia (which it shares with Tropical 

 America). Out of 21 American genera, 17 are endemic. Out of 

 a little over 100 American species, all but 2 are endemic. Very 

 few of the species occur in more than one of the climatic districts. 

 The two most widely dispersed plants of the order are Sisyrin- 

 chium Bermudianum^ which is common to Ireland and North 

 America, and Iris sihirica^ which extends from Sweden and France 

 to Japan, and just touches North-west America. There are 6 



plants which I have treated as species which are known in gardens 

 only. 



F 



I 



f 



f. 



h 

 I- 



