Description:

• Perennial, rarely annual, tufted, grass-like, usually marsh herbs, with a compact, erect rhizome (occasionally sub-bulbous in dry situations), usually gregarious
• Leaves radical, spirally arranged, narrowly ensiform, linear, terete or filiform, sheathing at base
• Inflorescence spicate, formed of tough bracts in an ovoid head terminating a long naked scape with a basal sheath
• Flowers bisexual, slightly irregular, 3-merous, fugaceous; scapes rarely with 1 or 2 pairs of sheathing bracts above; bracts glumaceous, spirally imbricate, bearing a solitary flower in its axil, the lower in some species leafy, forming an involucre
• Sepals 3, 2 lateral exterior, boat-shaped, glumaceous, third interior, membranous, forming a hood over the corolla in bud, circumscissile at base and deciduous at anthesis
• Corolla: lobes 3, regular, spreading, tubular below, with 3 slits; yellow, rarely white or blue
• Stamens 3, arising from corolla throat opposite lobes; anthers 2-thecous, dorsifixed, extrorse, opening lengthwise; staminodes 0-3, alternating with corolla lobes, modified, entire or 2-4-furcate, glabrous or variously plumose
• Ovary superior, 1-locular, with 3 parietal placentas or incompletely or completely 3-locular, with basal or axile placentas; ovules few-many; style simple, filiform, rarely with processes at or below middle, 3-fid or entire; stigmas dilated or filiform, oblique
• Fruit a 3-valvate loculicidal capsule enclosed in persistent corolla and sepals
• Seeds many, minute, spindle-shaped or globose, often with longitudinal moniliform ribs; embryo small, apical, surrounded by copious endosperm
• x = 9 (13) (aneuploids)

Nomenclature:

• Xyridaceae
  • Brown: 2 (1897)
  • Roessler: 1 (1967)
  • Dahlgren et al.: 388 (1985)
  • Obermeyer: 1 (1985)
  • Cook: 220 (1990)

Distribution & Notes:

• Global: Genera 5, species 260, 2 genera with aquatic species, mainly in tropical and subtropical areas of America, Australia, Asia and Africa
• Southern Africa: Genus 1, species 7

References:

• BROWN, N.E. 1897. Xyrideae. Flora capensis 7
• COOK, C.D.K. 1990. Aquatic plant book. SPB Academic Publishing, The Hague
• DAHLGREN, R.M.T., CLIFFORD, H.T. & YEO, P.F. 1985. The families of the monocotyledons. Springer-Verlag, Berlin
• OBERMEYER, A.A. 1985. Xyridaceae. Flora of southern Africa 4,2
• ROESSLER, H. 1967. Xyridaceae. Prodomus einer Flora von Südwestafrika 158

Resources:

• Xyridaceae genus: Xyris