Description :

• Evergreen herbs with a thick, creeping rhizome, persisting for several years
• Leaves several, ensiform, distichous, coriaceous, lanceolate, without a midrib, veins along centre of leaf sometimes crowded together
• Stem usually erect, bearing leaves at lower nodes, persisting for more than one season, with sheathing leaves at upper nodes; branching irregularly in upper half, or forming a divaricately branched panicle
• Inflorescences rhipidia, these terminal on branches; spathes coriaceous, tightly sheathing, outer smaller than inner
• Flowers actinomorphic, usually fugaceous or lasting up to 3 days in one species, several per rhipidium, borne serially, pedicels pubescent above; Iris-like, shades of white to yellow, style branches sometimes violet, limbs of outer tepals bearing contrasting markings near their bases, unscented, without nectar
• Tepals free, broadly unguiculate, claws ascending, limbs spreading, outer tepals larger than inner, with pubescent claws
• Stamens : filaments usually free, flattened and broader below, occasionally united below; anthers linear, appressed to style branch
• Ovary oblong to turbinate
• Style dividing shortly above base into 3 broad petaloid branches opposed to outer tepals, each branch terminating in a pair of erect petaloid appendages (crests); stigmas transverse, abaxial, below base of crests
• Capsules oblong to broadly ovoid or nearly hemispherical, apex truncate, cartilaginous to woody, irregularly rugose or smooth, tardily dehiscent or indehiscent, erect or pendent
• Seeds irregularly angled, fairly large, with a chalazal crest, rugulose, surface areolate
• x = 10 (polyploidy)

Classification Notes:

• Dietes is closely related to the northern hemisphere Iris and differs from it largely in having flowers without a perianth tube and the inner tepal limbs spreading rather than erect

Nomenclature:

• Dietes Salisb. ex Klatt
  • Klatt: 583 (1866) name conserved
  • Goldblatt: 141 (1981)
  • Goldblatt: 8 (1993)
• Naron Medik.
  • Medikus: 419 (1790) name rejected
• Moraea subgenus Dietes (Salisb. ex Klatt) Baker
  • Baker: 48 (1892); 11 (1896)

Distribution & Notes:

• Global : Species 6, 1 widespread species in eastern Africa, 1 on Lord Howe Island, Australasia; 5 in southern Africa
  • The geographic disjunction in the genus between Africa and Lord Howe Island is remarkable
  • The Lord Howe Island species, D. robinsoniana and the Eastern Cape D. bicolor are closely allied and primitive in the genus
• Southern Africa : Species 5

Additional Notes:

• The flowers are probably pollinated mainly by bees
• All the species grow in partly shaded habitats, often on forest margins or on the forest floor
• D. bicolor grows along perennial streams or rivers