Family Iridaceae
Synonyms: Geosiridaceae APNI*
Description: Perennial herbs, rarely annuals or small shrubs; rootstock a corm, bulb or rhizome.
Leaves usually distichous, basal or cauline, parallel-veined with closed basal sheaths, equitant, flat, variously winged or terete, sometimes dorsiventral and channelled.
Inflorescence terminal, usually scapose, either spicate with flowers solitary in a spathe of short bracts or cymose with spathes of 1 or 2 large outer bracts. Flowers actinomorphic or zygomorphic, 3-merous, bisexual. Perianth in 2 whorls; tepals 6, similar or dissimilar, free, or fused below in a tube. Nectaries usually present at base of tepals. Stamens mostly 3, inserted at base of the perianth or in the perianth tube opposite outer tepals; anthers 2-locular, basifixed to dorsifixed, usually extrorse, dehiscing by longitudinal slits. Ovary inferior, mostly 3-locular; ovules few–many, placentation axile; style usually 3-branched, sometimes further divided with a 3-lobed terminal stigma.
Fruit a capsule, opening loculicidally from apex, 3-valved; seeds sometimes arillate.
Distribution and occurrence: World: c. 90 genera, c. 1500 species, almost cosmopolitan, with centres of diversity in southern Africa, South America & Mediterranean region. Australia: 29 genera, 80 species, all States.
External links:
Angiosperm Phylogeny Website (Family: Iridaceae, Order: Asparagales)
Wikipedia Many exotic Iridaceae are grown widely in gardens and for cut flowers. Some including species of Homeria, Romulea and Watsonia, have become weeds.
Text by T. A. James & E. A. Brown
Taxon concept:
Taxa not yet included in identification key
Dietes
| | Key to the genera | |
| 1 | Inflorescence a solitary flower | 2 |
| Inflorescence of 2–many flowers | 3 |
| 2 | Inner perianth lobes less than one-third length of outer perianth lobes | Herbertia |
| Perianth lobes equal
Back to 1 | Romulea |
| 3 | Inflorescence cymose; each set of 2 spathe bracts enclosing 2–many usually pedicellate flowers, flowers withering and falling quickly | 4 |
| Inflorescence spicate; each set of 2 spathe bracts enclosing 1 sessile flower, flower not withering and falling quickly
Back to 1 | 12 |
| 4 | Style with petaloid branches, each covering a stamen, with 2 erect crests exceeding the flap-shaped stigma (Iris-shaped flowers) | 5 |
| Style without prominently crested petaloid branches; stamens exposed
Back to 3 | 6 |
| 5 | Plant evergreen with rhizomes; leaves several, erect; stamens free | Iris |
| Plant deciduous, with corms; leaf usually solitary, lax; stamens fused
Back to 4 | Moraea |
| 6 | Leaves folded longitudinally, or dorsiventral and channelled; individual flowers not subtended by bracteoles, only spathe bracts present | 7 |
| Leaves equitant; individual flowers subtended by bracteoles, spathe bracts present
Back to 4 | 8 |
| 7 | Leaves folded longitudinally; inner perianth lobes less than one-third length of outer lobes; rootstock a bulb | Herbertia |
| Leaves dorsiventral, channelled; perianth lobes more or less equal; rootstock a corm
Back to 6 | Moraea |
| 8 | Inner and outer perianth lobes very unequal, the inner lobes vestigial | Patersonia |
| Inner and outer perianth lobes unequal or subequal
Back to 6 | 9 |
| 9 | Flower zygomorphic; 2 stamens fertile, the third a staminode | Diplarrena |
| Flower actinomorphic; all 3 stamens fertile
Back to 8 | 10 |
| 10 | Flowers white; outer perianth lobes shorter and narrower than inner lobes | Libertia |
| Flowers blue, violet or creamy yellow often purple striped; perianth lobes equal in length
Back to 9 | 11 |
| 11 | Base of fan of leaves light green; style 3-branched | Sisyrinchium |
| Base of leaves reddish purple; style unbranched or occasionally with 3 very short lobes
Back to 10 | Aristea |
| 12 | Style branches deeply 2-fid; stigmas 6 or more | 13 |
| Style branches entire; stigmas 3
Back to 3 | 14 |
| 13 | Leaves coarsely fibrous in texture; flowers spreading in a loosely distichous vertical spike | Watsonia |
| Leaves soft-textured; flowers erect in a secund horizontal spike
Back to 12 | Freesia |
| 14 | Leaves pubescent, longitudinally folded, abruptly narrowed at base | Babiana |
| Leaves glabrous to very finely pubescent, never longitudinally folded or abruptly narrowed at base
Back to 12 | 15 |
| 15 | Flowers pendent on pendent filiform branches of a branched spike | Dierama |
| Flowers erect to horizontal; inflorescence unbranched or with erect branches
Back to 14 | 16 |
| 16 | Perianth tube straight; flowers more or less erect | 17 |
| Perianth tube curved; flowers spreading, often at right angles to axis
Back to 15 | 19 |
| 17 | Perianth tube narrowly cylindrical, exserted from spathes | Ixia |
| Perianth tube funnel-shaped, not or hardly exserted from spathes
Back to 16 | 18 |
| 18 | Spathes scarious, brown-streaked, ragged or lacerate | Sparaxis |
| Spathes membranous, at least partially green, not brown-streaked, entire or emarginate
Back to 17 | Tritonia |
| 19 | Axis of spike strongly flexuous; plant stoloniferous | Crocosmia |
| Axis of spike never flexuous; stolons absent
Back to 16 | 20 |
| 20 | Perianth tube swollen on 1 side near base, abruptly dilated c. 10 mm above ovary | Chasmanthe |
| Perianth tube gradually widened, never swollen on 1 side near base
Back to 19 | 21 |
| 21 | Spathe bracts entire, acute, herbaceous | Gladiolus |
| Spathe bracts toothed or lacerate, scarious
Back to 20 | Tritonia |
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