Iridaceae

Iris Family

By: George Rogers

Worldwide monocot family of about 70 genera and 1800 species.  Plants herbaceous with basal strap-shaped leaves usually meeting edge-to-edge (leaves "equitant").  Flowers with 6 usually colorful tepals (petals and sepals together) and 3 stamens, the stamens opposite the outermost tepals and sometimes resembling petals.  Ovary with 3 carpels, 3 chambers, and 3 styles, the styles sometimes resembling petals. Seeds black, numerous.  An important family for cultivated flowers (Belamcanda, Crocus, Dietes, Freesia, Gladiolus, Iris, Neomarica, Tigridia) and for wildflowers (Iris, Nemastylis, Sisyrinchium).

Key to Iridaceae Cultivated in South Florida

1.  Tepals united into a short tube; style branches resembling petals; flowers with 3 tepals drooping and 3 tepals erect…Iris

1.  Tepals free; style branches not resembling petals or resembling petals;  flowers with tepals variably oriented but not with 3 erect and 3 drooping…2

2.  Leaves < ½" wide, flowers blue with a yellow center, < ½" diam., in umbels; style branches not divided…Blue-Eyed Grass (Sisyrinchium) (in our area encountered most often as a wildflower, not in the manual)

2.  Leaves > ½" wide; flowers blue, yellow, or multicolored, > ½" diam., flowers in various arrangements but not umbels; style branches divided…3

3. Style branches deeply 3-parted…Tigridia (not often encountered and not in the manual)

3. Style branches 2-parted…4

4.  Style branches resembling petals; inner tepals variously marked but not with horizontal brown bars…Dietes…5

(Moraea is similar but has a corm (vs. rhizome) and the stamens are fused basally into a short tube.)

4. Style branches not resembling petals…6

5. Flowers mostly pale yellow, with orange and brown markings. Bracts 9-20 mm long, brown, paired; capsule globose…African Iris (Dietes bicolor)

5. Tepals white with yellow or orange markings, and with the styles purplish; capsule cylindrical. Bracts 25-50 mm long, green, not paired…African Iris (Dietes iridioides)

6. Flowers predominantly yellow…Yellow Walking Iris (Trimezia martinicensis, T. steyermarkii)

6. Flowers predominantly blue and white (with brown cross bars)…Neomarica caerulea, N. gracilis, and related cultivars (see discussion for comments on "Neomarica longifolia.")