IRIS FAMILY (Iridaceae)
PLEATED-LEAF IRIS PRAIRIE CELESTIAL WOODLAND CELESTIAL
Perennial herbs with bulbs, corms, or rhizomes; leaves usually basal and flattened at the sides; 3 sepals and 3 petals nearly equal; stamens 3; ovary below the perianth; fruit a 3-celled capsule.
Pleated-Leaf Iris (Herbertia caerulea) has pleated leaves like the celestials, but the flowers are quite different, the 3 sky-blue sepals being large and spreading and the 3 petals small and inconspicuous. The bases are white with violet markings. It is very abundant on the Coastal Plain of Louisiana and Texas in April and May. The name is in honor of William Herbert, a distinguished English botanist.
Prairie Celestial (Nemastylis acuta) has 6-parted sky-blue flowers with the 3 sepals and 3 petals nearly equal, white at the base. The 2-branched thread-like styles, from which the name is derived, spread horizontally between the 3 erect stamens. It grows on the prairies of North Texas to Kansas and Tennessee.
Woodland Celestial (Nemastylis texana) with its steel-blue flowers is more abundant in the southern part of the state in open post oak woods. Like the pleated-leaf iris, the flowers of the celestials open late in the morning and remain open only a few hours.
BLUE-EYED GRASSES
SWORD-LEAVED THUROW’S DWARF
Sword-Leaved Blue-Eyed Grass (Sisyrinchium ensigerum) is one of many blue-eyed grasses in the state, most of which have purplish-blue flowers, 6-parted and about half an inch broad, marked at the base with yellow. The flower has 3 erect united stamens. The flowers hang on thread-like stalks from two boat-shaped leaves about an inch long. The stems are winged, sword-shaped or outcurved, and have very fine saw-toothed edges. South-central to Northwestern Texas in April and May. In East Texas the prairie blue-eyed grass (Sisyrinchium campestre) is common. It has pale blue flowers, and the outer floral leaf is prolonged to a slender point, being 1½-2 in. long.
Dwarf Blue-Eyed Grass (Sisyrinchium minus) has small reddish-purple flowers and an oblong seed capsule. Coastal Plain, Louisiana to Texas. Spring.
Thurow’s Blue-Eyed Grass (Sisyrinchium thurowi) is a very small plant with small yellow flowers found in the southeastern part of the state in damp places. Spring.
GIANT IRIS
Giant Blue-Flag or Iris (Iris giganticaerulea) is a tall iris found in swampy places in East Texas and Louisiana, blooming in late April and May. The color of this iris is quite variable, ranging from dark violet to lavender and white. The recurved spreading sepals are 3-4 inches long, and the petals are shorter and erect. The capsules are 3-4 in. long with 6 rounded ridges.
Narrow Blue-Flag (Iris virginica) has been confused with the Carolina iris, according to Dr. Small of the New York Botanical Garden, who has recently described many new irises from Louisiana. The narrow blue-flag is colored similarly to the giant iris, but has shorter 3-angled capsules, very narrow leaves, and zig-zag stems. It is abundant on the Coastal Plain in early spring.
Red-Brown Flag (Iris fulva) is also found in the swamps in East Texas.