The World Flora Online

SELECTED REFERENCE

Kral, R. 1983d. The Xyridaceae in the southeastern United States. J. Arnold Arbor. 64: 421--429.

Herbs, perennial or annual, mostly heliophytes of acidic wetlands, rarely aquatic. Leaves alternate, 2-ranked (occasionally many-ranked); base equitant, sheathing or open, sometimes with ligule or auricles at junction; blade mostly linear or filiform, flat to variously thickened and/or sulcate [lingulate], margins entire to papillate or scabrous; venation parallel. Inflorescences terminal; scape sheaths proximally tubular, distally open, bladed; scapes erect, linear to filiform, not bracteate [bracteate]; spikes single [cluster, rarely panicle of spikes], conelike; bracts chaffy. Flowers bisexual, radially [bilaterally] symmetric; sepals [2--]3, unequal [equal], outer 2 (lateral sepals) nearly opposite, connivent to variously connate, clasping mature capsule, inner sepal membranous (occasionally similar to others or absent), abcissing as flower opens; petals 3, equal [unequal], distinct [connate]; stamens 3; staminodes (0--)3, 2-brachiate, free [adnate to perianth or absent]; anthers 4-sporangiate, 2-locular at anthesis; pollen monosulcate or inaperturate; ovaries y superior, 1[--3]-locular; ovules anatropous; styles 1, distally 3-branched [simple]; stigmas 3 [1, 3-lobed, capitate, or funnelform]. Fruits capsular, mostly loculicidal. Seeds [1--6--]15--90 or more, mostly under 2[--4] mm, mostly ridged or lined.

Herbes'vivaces, plus rarement annuelles ; partie souterraine souvent bulbeuse ou rhizomateuse ; système radiculaire fasciculé.'Feuilles'simples, groupées en rosette basilaire, sessiles, distiques ou arrangées en spirale, linéaires à cylindriques ou parfois filiformes, à base engainante. Inflorescences en épis denses, globuleux, ovoïdes à cylindriques, au sommet d'une hampe florale ; très rarement inflorescences cymeuses ; bractées densément imbriquées, les basilaires involucrales, stériles, les supérieures fertiles.'Fleurs'hermaphrodites, 3-mères, actinomorphes ou partiellement zygomorphes, à enveloppe florale hétérochlamydée ; corolle à pétales libres ou soudés en tube dans la partie inférieure ; étamines 3, épipétales, à filets libres ; staminodes 3, plumeux, ou absents ; gynécée supère, uniloculaire ou incomplètement 3-loculaire, à placentas pariétaux, basaux ou centraux ; ovules nombreux, orthotropes ; style 1, à 1-3 stigmates.'Fruits'capsulaires, loculicides.'Graines albuminées.\n\t\t\tFamille pantropicale et subpantropicale, comprenant 4 genres et env. 280 espèces. En Afrique 1 genre : Xyris.

Fruit a capsule enclosed in the persistent, corolla-tube Perennial or annual herbs Seeds numerous, with copious endosperm and small embryo Corolla with a short or long tube and 3 equal spreading lobes Stamens 3, opposite the corolla-lobes, and 3 alternate staminodes or the latter absent; anthers 2-locular, opening by slits Ovary superior, 1-locular, with 3 parietal placentas or imperfectly 3-locular at the base; style simple or 3-lobed Ovules numerous to few Leaves mostly radical, tufted, linear, terete or filiform, sheathing at the base Sepals 3 or rarely 2, the lateral 2 exterior, boat-shaped, keeled, glumaceous, the third interior, membranous, forming a hood over the corolla and pushed aside as the latter develops Flowers hermaphrodite, slightly zygomorphic, arranged in pedunculate terminal globose or cylindrical heads; bracts imbricate, leathery or rigid, the lower sometimes forming an involucre Perennial or annual herbs Seeds numerous, with copious endosperm and small embryo Corolla with a short or long tube and 3 equal spreading lobes Stamens 3, opposite the corolla-lobes, and 3 alternate staminodes or the latter absent; anthers 2-locular, opening by slits Ovary superior, 1-locular, with 3 parietal placentas or imperfectly 3-locular at the base; style simple or 3-lobed Ovules numerous to few Leaves mostly radical, tufted, linear, terete or filiform, sheathing at the base Sepals 3 or rarely 2, the lateral 2 exterior, boat-shaped, keeled, glumaceous, the third interior, membranous, forming a hood over the corolla and pushed aside as the latter develops Flowers hermaphrodite, slightly zygomorphic, arranged in pedunculate terminal globose or cylindrical heads; bracts imbricate, leathery or rigid, the lower sometimes forming an involucre

Fls hypogynous, perfect, usually entomophilous but without nectaries or nectar; sep typically 3, the upper (anterior, adaxial) one thin and membranous, ± enclosing the pet and abscising as the fl opens, or sometimes reduced or obsolete; lateral sep 2, boat-shaped, keeled, chaffy-scarious, persistent and clasping the capsular fr; pet 3, ephemeral, nearly or quite alike, yellow or sometimes white or blue, long-clawed and distinct, or connate below into a slender tube; stamens mostly 3, opposite and basally adnate to the pet, often alternating with staminodes; ovary tricarpellate, typically (incl. our spp.) unilocular with 3 parietal (often ± intruded) placentas each bearing several or many ovules; embryo small, scarcely differentiated into parts, lying alongside the base of the copious, mealy endosperm; herbs; lvs mostly or all basal, with an open sheath and narrow, parallel-veined (or univeined), very often equitant and unifacial blade; scapes or peduncles each usually terminating in a head or dense spike with the fls sessile in the axils of firm, spirally arranged, closely imbricate bracts. 4/nearly 300 spp.

Leaves alternate, simple, linear, distichous, few to numerous, basal sheath open, blade flattened to terete Flowers 3-merous, bisexual; calyx-lobes 3, the adaxial at first forming a hood-like structure over the bud, the laterals smaller; corolla tubular, divided above into 3 broad spreading usually yellow but sometimes white, blue or orange petals Inflorescence a condensed pedunculate spike; flowers in the axils of densely crowded often coriaceous bracts, forming a spherical, ovoid or elongate head (the spike) Ovary (1–)3-locular, with numerous ovules and axile or parietal placentation; style 1, sometimes divided into 3 at the apex Stamens 3, opposite the petals, often with 3 staminodes alternating with them Seeds numerous, small, with endosperm Fruit a loculicidal or irregularly dehiscent capsule Annual or perennial herbs, often in seasonally or permanently wet sites; stems upright, base sometimes swollen in perennial species Flowers 3-merous, bisexual; calyx-lobes 3, the adaxial at first forming a hood-like structure over the bud, the laterals smaller; corolla tubular, divided above into 3 broad spreading usually yellow but sometimes white, blue or orange petals Inflorescence a condensed pedunculate spike; flowers in the axils of densely crowded often coriaceous bracts, forming a spherical, ovoid or elongate head (the spike) Ovary (1–)3-locular, with numerous ovules and axile or parietal placentation; style 1, sometimes divided into 3 at the apex Stamens 3, opposite the petals, often with 3 staminodes alternating with them Seeds numerous, small, with endosperm Fruit a loculicidal or irregularly dehiscent capsule Annual or perennial herbs, often in seasonally or permanently wet sites; stems upright, base sometimes swollen in perennial species

Herbs perennial or rarely annual. Roots fibrous. Leaves mostly basal, distichous or sometimes polystichous, sheathing; leaf blade ensiform, linear, or filiform. Scapes or peduncles usually numerous. Inflorescence terminal, a globose to cylindric head or dense spike; bracts conspicuous, spirally imbricate or decussate, persistent or sometimes caducous in fruit. Flowers bisexual, 3-merous. Sepals 3, sometimes median sepal reduced or absent, lateral sepals 2, chaffy-scarious, keeled. Corolla actinomorphic or rarely zygomorphic, usually ephemeral; petals 3, yellow, less often white or blue, free, base clawed or sometimes connate, or forming a long tube. Stamens usually 3, inserted opposite petals; filaments short, adnate to petals, rarely free; anthers 2-loculed, dehiscing longitudinally. Staminodes present or absent. Ovary superior. Style filiform, apex 3-branched or simple. Capsule oblong, 3-valved, loculicidal. Seeds with copious and ± mealy endosperm; embryo small.