SPERMATOPHYTA— IRIDACEAE 389 



the Carolina blue flag (/. Carolina) of the South, blue eyed grass (Sisyrinchium 

 angustifolium) . Many species of the exotic blue flags, Iris like the dwarf gar- 

 den iris (/. pumila) and the common flower-de-luce (/. germanica), the common 

 crocus or saffron (Crocus vernus) used for coloring, freesia (Freesia refracta), 

 tritonia and gladiolus are cultivated for ornamental purposes. The orris root 

 (Iris florentina, I. pallida and /. germanica) is an article of commerce used for 

 perfume and tooth powders. It contains myristic acid. A substitute for saffron 

 is obtained from the flowers of the South American saffron {Crocosmia aurea). 



Fig. 169a. The petaloid bilobed stigma and 

 tamen of Iris. (Kerner). 



stamen of Iris. (Kerner). 



Iris (Tourn) h. 



Herbs with creeping or horizontal root stocks, and erect stems with equi- 

 tant leaves ; flowers large, regular, panicled ; perianth of 6 segments united below 

 into a tube, the outer dilated, spreading or reflexed ; the 3 inner, smaller ; stamens 

 inserted at the base of the outer perianth ; ovary 3-celled ; fruit a capsule ; 

 seeds numerous. About 100 species in the North Temperate regions. The 

 Iris florentina contains the glucoside irigenin C „H 0„. This is derived from 

 irisin. 



Iris versicolor, L. 



Root stock fleshy; stem roundish; leaves erect, leaves shorter than the 

 stem; flowers bluish, perianth deeply 6-parted, the 3 outer divisions reflexed, 

 the 3 inner smaller, erect; stamens distinct, covered by the petaloid stigmas. 



Distribution. In marshes, thickets, and wet meadows from Newfoundland 

 to Manitoba, south to Florida and Arkansas. 



Poisonous properties and uses. The root contains the substance irisin, 

 or iridin. The acrid resinous substance, irisin, acts powerfully upon the gas- 

 tro-intestinal tract, liver and pancreas, causing a burning sensation and conges- 

 tion. That the root is poisonous may be seen from the following statement 

 made by Dr. Rusby : 



Another rhizome whose acrid taste is likely to prevent ingestion in poisonous quantity, 

 is that of the common Iris versicolor, L. Still, because this is commonly known as the 

 blue flag, there is some danger that it might be eaten in mistake for calamus, which is 

 commonly known as sweet-fiag. If so, it would prove seriously, if not fatally poisonous 



