. . . what, where, when, how . . .. . . what, where, when, how . . .Diversity and EvolutionDiversity and Evolutionof Monocotsof MonocotsMonocots!Monocots!We will finish our survey ofWe will finish our survey ofangiosperms by examining theangiosperms by examining themonocotsmonocots - a lineage of basal - a lineage of basalangiospermsangiospermsBasal angiosperm lineage, but isBasal angiosperm lineage, but isappearing to be closer to eudicotsappearing to be closer to eudicotsthan most other basalthan most other basalangiospermsangiospermsMonocots!Monocots!•• Large groupLarge group: ~ 60,000 species!: ~ 60,000 species!•• Old lineageOld lineage: ~134 mya: ~134 mya•• Great diversityGreat diversity: habit, habitat, pollination, morphology: habit, habitat, pollination, morphology•• Adaptive radiationsAdaptive radiations: : (orchids(orchids––21,950 spp; grasses21,950 spp; grasses––10,035 spp)10,035 spp)# $%@!# $%@!•• Smallest & largest seeds: orchids; Smallest & largest seeds: orchids; Lodoicea maldivicaLodoicea maldivica•• Largest inflorescences (titan arum, palms, bromeliads) Largest inflorescences (titan arum, palms, bromeliads)•• Smallest fruit, flower & flowering plant ( Smallest fruit, flower & flowering plant (WolfiaWolfia))Tremendous economicTremendous economicimportanceimportanceDiversity in ecologyDiversity in ecology••Trees, grasses, rosettes,Trees, grasses, rosettes,vines, epiphytesvines, epiphytes……••Carnivores, mycotrophsCarnivores, mycotrophs……••Habitats: dry, wet,Habitats: dry, wet,aquaticaquatic……••Pollination: water, wind,Pollination: water, wind,zoophilyzoophilyEmergentEmergent, , floatingfloating, or , or submergedsubmergedaquatic group of monocotsaquatic group of monocotsThese are the first divergingThese are the first divergingmonocotsmonocotsemergentemergentfloatingfloatingsubmergedsubmergedDiversity of aquatic habitsDiversity of aquatic habitsMonocot Monocot ““treestrees””No vascular cambium activity No vascular cambium activity ⇒⇒ no true secondary growthno true secondary growth (wood) (wood)Anomalous secondary growth Anomalous secondary growth ⇒⇒ ““treestrees””Dragon tree Dragon tree –– a lily relative a lily relativeWoody palmWoody palmMonocot leavesMonocot leaves•• Parallel venationParallel venation (or (orderived forms) vs.derived forms) vs.pinnate or reticulatepinnate or reticulatevenation as in mostvenation as in mostdicotsdicots•• (more on this later) (more on this later)Monocot flower: common themeMonocot flower: common theme3-merous3-merousTepalsTepals are common are commonDiversity in pollinationDiversity in pollinationStriking modifications & bracts:Striking modifications & bracts:grasses, pulpits, orchids, spadices & more!grasses, pulpits, orchids, spadices & more!Monocots have usually beenMonocots have usually beenconsidered as derived out of considered as derived out of basalbasalangiospermsangiosperms - Ranales in the Bessey - Ranales in the Besseysystem or subclass Magnoliidaesystem or subclass Magnoliidaewith Cronquistwith CronquistMonocot OriginsMonocot OriginsFossil recordFossil recordCrown group radiation: ~Crown group radiation: ~134 134 myamya [based on DNA evidence][based on DNA evidence]Pollen & leaf: possible early Pollen & leaf: possible early AptianAptian ( (Early CretaceousEarly Cretaceous), 113-125 ), 113-125 myamyaOldestOldest unambiguously assigned unambiguously assigned fossilfossil: : AraceaeAraceae, 110-120 , 110-120 myamyaCronquistCronquist’’s views view1.1.HerbsHerbs2.2.AquaticAquatic3.3.PerianthPerianth not specialized not specialized4.4.Uni-apperturateUni-apperturate pollen pollen5.5.ApocarpyApocarpy6.6.Laminar placentationLaminar placentationClassic idea of pre-monocotClassic idea of pre-monocotcharacteristics:characteristics:NymphaealesNymphaealesOnly non-monocotOnly non-monocotorder with all theseorder with all thesecharacteristicscharacteristicsCronquistCronquist’’s views view•• monocot leaf morphology due to monocot leaf morphology due to aquaticaquaticancestryancestry•• aquatic aquatic èè terrestrial terrestrial èè aquatic pathwaysaquatic pathwaysCronquistCronquist’’s views view•• monocot leaf is derived from an monocot leaf is derived from an expandedexpandedbladeless petiolebladeless petiolecelery (left) and tomato (right) celery (left) and tomato (right) asteridasterid petioles showing petioles showingparallel vascular tracesparallel vascular tracesMonocot leaves Monocot leaves –– phyllode theory phyllode theoryPhyllode theoryPhyllode theory: original monocot: original monocotlacked a true leaf; only lacked a true leaf; only expandedexpandedpetiolepetiolePhyllodesPhyllodes: expanded : expanded blade-lessblade-lesspetiolespetioles best seen in arid best seen in aridadapted woody legumes such asadapted woody legumes such asAcaciaAcaciaMonocot leaves Monocot leaves –– phyllode theory phyllode theoryvariablevariableexpansion ofexpansion oftissuetissuebetweenbetweenparallel veinsparallel veinscross veins &cross veins &‘‘reticulatedreticulated’’bladesbladesAcorusAcorussweet flagsweet flagloss of bladeloss of blade& expansion& expansionof tissueof tissuebetweenbetweenparallel veinsparallel veinsof petioleof petiolein aquatic habitatin aquatic habitatMonocot leaves Monocot leaves –– phyllode theory phyllode theoryloss of bladeloss of blade& expansion& expansionof tissueof tissuebetweenbetweenparallel veinsparallel veinsof petioleof petiolevariablevariabledivergencedivergenceof parallelof parallelveins toveins toleaf edgeleaf edge‘‘parallel-pinnateparallel-pinnate’’venation of palmsvenation of palmsand bananasand bananasin aquatic habitatin aquatic habitatNet venation & fleshy fruitsNet venation & fleshy fruitsfunctional ecological arguments for evolution of functional ecological arguments for evolution of broad leaves broad leaves and and fleshy fruitsfleshy fruitsof monocots of monocots in shady understory in shady understory conditions (T. Givnish, 1984, 1999, 2002)conditions (T. Givnish, 1984, 1999, 2002)Occurrences of Occurrences of net venationnet venation are areoverlain on this phylogenyoverlain on this phylogenyConcertedConcertedconvergenceconvergenceOccurrences of Occurrences of net venationnet venation and andfleshy fruitsfleshy fruits are overlain on this are overlain on thisphylogenyphylogenyBoth features:Both features:••