Iris prismatica, the slender blue flag or cubeseed iris,[2] is a plant species native to parts of the southern and eastern United States from Maine south to Alabama, as well as to the Canadian provinces of Ontario and Nova Scotia.[3][4][5]
| Slender blue flag | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Asparagales |
| Family: | Iridaceae |
| Genus: | Iris |
| Subgenus: | Iris subg. Limniris |
| Section: | Iris sect. Limniris |
| Series: | Iris ser. Prismaticae |
| Species: | I. prismatica |
| Binomial name | |
| Iris prismatica Pursh | |
| Synonyms[1] | |
| |
Iris prismatica is a perennial herb spreading by means of rhizomes that are close to the surface of the soil. Flowering stalks can reach a height of 80 cm. Leaves are long and narrow, up to 60 cm long but rarely more than 5 mm across. It has 2–3 blooms in May.[2] Flowers are pale blue to blue-violet.[6][7][8][9][10] It tends to grow in swampy,[2] wet conditions,[3] and within the United States, it is currently state listed as 'threatened' in Maine, New Hampshire, New York, and Tennessee, and state listed as 'endangered' in Maryland and Pennsylvania.[11] It is cold hardy to USDA Zone 3.[2]