76 THE BOOK OF THE IRIS 



recognised, with /. setosa, among species with ensiform 

 leaves by its small standards. From /. setosa it may 

 be known by its glaucescent leaves. They are I to 

 ij ft. long by f in. broad. The stems overtop the 

 leaves, are two to three headed, and bear two to 

 three large leaves ; pedicels an inch or more long ; 

 perianth-tube cylindrical, \ to in. long ; limb bright 

 lilac, 2 to 2 J in. long ; falls with nearly round blade an 

 inch broad, as long as the haft, and suddenly narrowed 

 to it ; standards erect, obovate, \ in. long ; crests 

 small, deltoid. Habit of /. versicolor, but easily dis- 

 tinguished by its standards. Native of Canada. 



22. I. setosa, Pallas ; Regel, Gartenfl., t. 322 ; 

 1. brachycuspis, Fisch in Sot. Mag., t. 2326. A well- 

 known but not a popular Iris. The rhizome is stout, 

 sheaths splitting into fine fibres ; leaves thin, green, 

 I to ij ft. long, | to I in. broad; stem deeply forked, 

 much overtopping the leaves, bearing two to three heads 

 and two to three large leaves ; spathes two to three 

 flowered; pedicels, I to ij in. long; perianth-tube 

 cylindrical, ^ in. long ; limb bright lilac, 2 to 2 j in. 

 long ; falls with orbicular blade more than an inch broad, 

 narrowed suddenly to much veined haft ; standards 

 | in. long, cuneate, with large cusp ; crests deltoid. 

 Native of Eastern Siberia, Japan and N.W. America. 



23. I. Pseudacorus, Linn. Eng. Bot., t. 578 (vol. 

 ix. of 3rd ed.). This is the Yellow Flag, common 

 throughout Britain along river banks and ditches. It is 

 known also as the Yellow Water Iris, Jacob's Sword, 

 Water Flag and Yellow Fleur de Luce. So familiar a 

 plant can hardly need much description. It has a stout, 

 creeping, acrid rhizome ; leaves 2 to 4 ft. long, \ to 

 I in. broad ; stem 2 to 4 ft. high, leafy, often branched 

 at the top ; pedicel about as long as the ovary ; flowers 

 3 to 4 in. in diameter, variable in shade of yellow colour 

 and in form of segments ; tube cylindric ; falls often 



