IRIDACE^E IRIS FAMILY 



Iris prismatica, Pursh. 



Violet-blue Slender Blue Flag, 



Narrow Blue Flag, 

 May- June Poison Flag-root. 



Iris: from Greek for rainbow. 



Prismatica: from Greek for a prism because of the prismatic 

 shape of the seed-vessels. 



THE PREFERRED HABITAT: open, damp ground, or even 

 dry, sandy soil. 



THE PLANT: erect, from a slender, tuberous and thickened 

 underground stem, one foot to three feet tall; the flower- 

 stem usually simple, without hairs. 



THE LEAVES: two or three, basal, and scattered up the 

 stem ; grass-like ; mostly shorter than the stem ; hairless on 

 both sides; acute at the apex; entire; parallel-veined. 



THE FLOWERS: large, solitary or two together, on slender 

 stems, blue- veined with yellow markings; the outer parts 

 of the flower sometimes two inches long, usually less, 

 hairless; the inner smaller. 



THE FRUIT: a narrowly oblong capsule, acute at each end, 

 with three deep angles. 



The prismatica and versicolor are similar, but the pris- 

 matica, once known, is easily distinguishable by its more 

 slender build, by its grass-like leaves, and, when in fruit, 

 by the slender and distinctly prismatic seed-vessel, which 

 is quite different from the cylindric and well-rounded 

 seed-vessel of the versicolor. 



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