54° 



IRIDACEAE. 



Vol. I. 



10. Iris Pseudacorus L. Yellow or Sword-flag, 

 Corn-flag. Fig. 1337. 



Iris Pseudacorus L. Sp. PI. 38. 1753. 



Rootstock thick. Stems ii°-3° high, usually several- 

 flowered; leaves pale green and glaucous, stiff, 4"-8" 

 wide, the lower equalling or longer than the stem; 

 flowers bright yellow, short-pedicelled ; perianth-seg- 

 ments glabrous and crestless, the outer broadly obovate, 

 a'-2i' long, the inner oblong, nearly erect, scarcely 

 longer than the claws of the outer ones; capsule ob- 

 long, 2-3' long. 



In marshes, Massachusetts to southern New York and 

 New Jersey. Naturalized or adventive from Europe. False 

 Sweet-flag. Yellow Water-flag or -skegs. Jacob's-sword. 

 Daggers. Flagons. May-July. 



Iris orientalis Mill., native of Asia, with pale yellow 

 flowers and short stem-leaves, is reported as escaped from 

 cultivation into marshes on the coast of Connecticut, 



11. Iris cristata Ait. Crested Dwarf Iris. 

 Fig. 1338. 



Iris cristata Ait. Hort. Kew. 1 : 70. 1789. 



Rootstock slender, branched, creeping, tuber- 

 ous-thickened. Stems only i'-3' high, 1-2- 

 flowered; leaves lanceolate, bright green, 4'-o/ 

 long, 3" -9" wide, much exceeding the stems; 

 scape flattened, flowers blue, pedicelled; perianth- 

 segments obovate, i'-ii' long, the outer crested, 

 little longer than the naked inner ones, the tube 

 very slender, 1Y-2Y long above the ovary, longer 

 than the bracts; capsule oval, sharply triangular, 

 narrowed at each end, 6"-g" high, 4,"-$" thick. 



On hillsides and along streams, Maryland to south- 

 ern Ohio and Indiana, south to Georgia, Tennessee 

 and Missouri. April-May. 



12. Iris lacustris Nutt. Dwarf Lake-iris. 

 Fig- 1339- 



Iris lacustris Nutt. Gen. 1 : 23. 181 8. 



Similar to the preceding species in size and 

 foliage, or the leaves rather narrower, sometimes 

 wavy-margined. Flowers blue; perianth-tube 

 only i'-i' long, shorter than the bracts and 

 the sometimes yellowish perianth-segments some- 

 what expanded upward; capsule ovoid, about 8" 

 high, borne on a pedicel of about its own length. 



Shores of Lakes Huron, Michigan and Superior. 

 Local. May. Perhaps a race of the preceding species. 



