1Inflorescences - Floral DisplaysInflorescences - Floral DisplaysThe vast majority of flowering plantsThe vast majority of flowering plantspossess flowers in clusters called anpossess flowers in clusters called aninflorescenceinflorescence..These clusters facilitate pollination viaThese clusters facilitate pollination viaa prominent visual display and morea prominent visual display and moreefficient pollen uptake and deposition.efficient pollen uptake and deposition.A shift from widelyA shift from widelyspaced single flowers tospaced single flowers toan inflorescence requiredan inflorescence requiredcondensation of shootscondensation of shootsand the loss of theand the loss of theintervening leaves.intervening leaves.((PrunusPrunus or cherry)or cherry)The simplestThe simplestinflorescence typeinflorescence typewould thus bewould thus beindeterminateindeterminate with the with theoldest flowers at theoldest flowers at thebase and the youngerbase and the youngerflowers progressivelyflowers progressivelycloser to the apicalcloser to the apicalmeristem meristem of the shoot.of the shoot.= a = a racemeracemeRacemeRacemeRacemeRacemeOne modification of the basic raceme is to make it compoundOne modification of the basic raceme is to make it compoundcompoundcompoundPaniclePanicleThe The paniclepanicle is essentially is essentiallya series of attacheda series of attachedracemes with the oldestracemes with the oldestracemes at the base andracemes at the base andthe youngest at the apexthe youngest at the apexof the inflorescence.of the inflorescence.((ZigadenusZigadenus or white camass)or white camass)Panicle2RacemeRacemeA second modification of the basic raceme is to lose its pedicelsPedicel lossPedicel lossSpikeSpikeThe spike is usuallyassociated with congestedreduced flowers and often,but not always, with windpollination.((PlantagoPlantago or plantain)or plantain)SpikeSpikewind pollinatedwind pollinatedThe spike is usuallyassociated with congestedreduced flowers and often,but not always, with windpollination.SpikeSpikeanimal pollinatedanimal pollinated((CombretumCombretum - Brent- Brent’’s plants)s plants)RacemeRacemeA third modification of the basic raceme is to lose its internodesA third modification of the basic raceme is to lose its internodesInternode Internode losslossUmbelUmbel3The The umbelumbel characterizes specific families (carrot and characterizes specific families (carrot andginseng families for example).ginseng families for example).These families typically show a compound umbel -These families typically show a compound umbel -smallersmaller umbelletsumbellets on a larger umbel.on a larger umbel.((CicutaCicuta or water hemlock)or water hemlock)UmbelUmbel((ZiziaZizia or golden alexander)or golden alexander)The The umbelumbel is found scattered in many other families is found scattered in many other familiesas well.as well.((EriogonumEriogonum or false buckwheat - familyor false buckwheat - familyPolygonaceaePolygonaceae) - Ben) - Ben’’s plantss plantsUmbelUmbelRacemeRacemeA fourth modification of the basic raceme is for the stem axis to form a headA fourth modification of the basic raceme is for the stem axis to form a headStem headStem headHead orHead or capitulum capitulumThe The head orhead or capitulum capitulum characterizes specificcharacterizes specificfamilies - most notably thefamilies - most notably the Compositae Compositae ororAsteraceaeAsteraceae. Not surprisingly, this family is closely. Not surprisingly, this family is closelyrelated to families possessing umbels.related to families possessing umbels.((HelianthusHelianthus or sunflower) or sunflower)Head orHead or capitulum capitulum4Besides these indeterminate inflorescences based on theBesides these indeterminate inflorescences based on theraceme, there is a series of inflorescence types based onraceme, there is a series of inflorescence types based ondeterminatedeterminate shoots (shoot can not grow up indefinitely). shoots (shoot can not grow up indefinitely).The simplest is the The simplest is the dichasiumdichasium..RacemeRacemeDichasiumDichasiumThe The dichasiumdichasium inflorescence isinflorescence isterminated (i.e., determinate) by theterminated (i.e., determinate) by theoldest flower and flanked by two lateraloldest flower and flanked by two lateralyounger flowers.younger flowers.DichasiumDichasium((ClematisClematis or virgin or virgin’’s-bower)s-bower)oldest floweroldest floweryounger flowersyounger flowersOne modification of the basic One modification of the basic dichasium dichasium is to make it compoundis to make it compoundDichasiumDichasiumCymeCymecompoundcompoundCymeCyme((SileneSilene or or campioncampion))The The cymecyme characterizes specific families - mostcharacterizes specific families - mostnotably the notably the Caryophyllaceae Caryophyllaceae - the pink or- the pink orcarnation family . . .carnation family . . .5CymeCyme((LisianthiusLisianthius))or the or the Gentianaceae Gentianaceae - the gentian family.- the gentian family.A second modification of the basic A second modification of the basic dichasium dichasium is to reduce itis to reduce itDichasiumDichasiumMonochasiumMonochasiumreductionreductionScirpoidScirpoid((MertensiaMertensia or bluebell)or bluebell)The The monochasiummonochasium is most often seen in compoundis most often seen in compoundform as aform as a scirpoidscirpoid inflorescence.inflorescence. The TheBoraginaceae Boraginaceae (Virginia bluebell family) is(Virginia bluebell family) ischaracterized by this distinctive inflorescence.characterized by this distinctive inflorescence.Another specialized inflorescence is the Another specialized inflorescence is the catkincatkin or or amentament•• unisexual cluster of small flowers unisexual cluster of small flowers•• apetalous apetalous (without petals)(without petals)•• hard bracts around the flowers hard bracts around the flowers•• wind pollinated wind pollinated•• falls as a unit falls as a unit((PopulusPopulus or cottonwood)or cottonwood)[male catkin][male catkin][female catkin][female catkin]((QuercusQuercus or white oak)or white oak)[male catkin][male catkin]6A final specialized inflorescence is the A final specialized inflorescence is the spadixspadix•• thickened, fleshy spike thickened, fleshy spike•• associated with associated with spathespathe bractbract•• frequently flowers unisexual frequently flowers unisexual•• best