Taxonomy  and  Botany  Rivanna  Master  Naturalists  

•  March  24,  2015  

Taxonomy

•  Taxonomy: the science of discovering, describing, naming, & classifying life

•  classification systems: – early humans: utility (plants: good food,

poisonous, other uses such as medicinal) – horticulturalists: “woodies”(trees and shrubs),

annuals, perennials

MODERN  CLASSIFICATION  SYSTEMS  

 Goal:  Categorize  life  based  upon    evoluOonary  relaOonships  

•  Before  DNA  analysis,  morphological,  chemical,  other  available  informaOon  used  in  classificaOon.  

•  Now,  use  molecular  data,  primarily  DNA,  led  to  much  re-­‐classificaOon  of  living  things.  Example:  birds  in  Australia  

Australian  fairy-­‐wren  

Flowering  dogwood:  classificaOon    

•  Add  photo  of  Flowering  dogwood  

Biological classification of Flowering Dogwood

•  Kingdom: Plantae Division: Anthophyta

Class: Angiospermae Order: Cornales

Family: Cornaceae Genus: Cornus Species: florida

Common  vs  scienOfic  name  

Flowering  dogwood:  Cornus  florida  Humans:  Homo  sapiens    Binomial  system  of  nomenclature:  

 Genus  and  species  name    IdenOficaOon  using  dichotomous  key  

Erythronium  americanum  Common  Names    

•  Trout  lily  •  Fawn  lily  •  Adder’s  tongue  •  Dog-­‐tooth  violet  

Six  kingdoms  

•  Archaebacteria  •  Eubacteria  •  ProOsta  •  Fungi  •  Animalia  •  Plantae  

Kingdom:  Archaebacteria        

•  most  ancient  bacteria  •  Grow  in  harsh  environments:  heat,  saline  

Kingdom  Eubacteria    

•  More  advanced  bacteria  

•  Some  photosyntheOc  

•  Some  can  “fix”  Nitrogen  change  gas  to  nitrates;  live  in  root  nodules  in  bean  family  

Kingdom  Fungi  

•  Mushrooms,  molds,  lichens  

•  Mycorrhizae  associated  with  roots  of  vascular  plants  for  mutual  aid  

•  Lichens:  alga  +  fungus:  extreme  environments:  deserts,  polar,  high  elevaOon;  SensiOve  to  pollutants  in  air  

SOnky  squid  fungus  

Kingdom  ProOsta  

•  Algae:  red,  green,  brown;  seaweeds  

•  Protozoa:  usually  one-­‐celled:        Paramecium,  Amoeba,  Euglena  

ProOsta:  green  algae  

ProOsta:  Amoeba  

Kingdom  Animalia  

•  Invertebrates:  sponges  through  starfish  

•  Vertebrates:  lampreys  and  fish  through  mammals  including  humans    

Flatworms:  Planaria  

Annelida:  Polychaete  worm  

Phylum  Arthropoda  

Echinodermata:  Feather  star  

Invertebrates  

•  Stay  tuned…will  be  shown  during  Michelle’s  Ecology  presentaOon  

Chordata:  vertebrates  

Kingdom  Plantae  

•  Non-­‐vascular:  Bryophytes:  mosses,  liverworts,  hornworts  

•  Vascular  (specialized  Ossue  that  conducts  water,  minerals,  sugars)  

 a.  Seedless:  ferns,  club  mosses  horse  tails    b.  Seed  plants  

Non-­‐vascular:  Moss  (and  Moss  ManOs)  

Vascular,  seedless:  Fern  

Vascular,  seedless:  Club  moss  

Seed  plants  

•  Gymnosperms  Naked  seeds:  conifers,  gingko  

•  Angiosperms:  Covered  seeds:  flowering  plants  

– Monocots:  one  seed  leaf  (corn)  

– Dicots:  two  seed  leaves  (radishes,  beans)  

Gingko  tree  

Conifer:  white  pine  

Parts  of  an  Angiosperm    

1.  Roots:  uptake  of  water,  minerals;  anchor  

2.  Stems:  support;  transport  of  water,  sugars    3.  Leaves:  Photosynthesis:  Carbon  dioxide  +  water  in  presence  of  chlorophyll  and  light  yields  sugar  +  water    4.  Flowers  

Parts  of  an  Angiosperm  

SecOon  through  leaf  

Flowers  

•  Petals  or  not:  depends  on  method  of  pollinaOon,  wind  or  animals  

•  Parts:  sepal  (calyx),  petal  (corolla),  stamen  (male),  pisOl  (female),  receptacle  

         

Alstromeria  

Spring  beauty  

FLOWERING  PLANT  REPORDUCTION  

Dicot  seed:  lima  bean  

PLANT  PHYSIOLOGY  

Nitrogen  metabolism  

•  Plants  need  N-­‐compounds  to  sustain  life.    •  May  take  them  up  as  N-­‐compounds  dissolved  in  water  taken  up  by  roots  

•  Some  plants  including  legumes,  have  evolved  symbioOc  relaOonships  between  bacteria  that  can  fix  N  and  themselves.  Bacteria  housed  in  nodules  of  roots  

Nitrogen  metabolism  N-­‐fixing  bacteria  in  nodules  of  

legume    

PLANT  MOVEMENTS  

•  Plants  have  no  muscles  and  nerves  •  All  movement  by  plants  are  through  growth  or  turgor  pressure  changes:  slow  or  fast  

•  Slow:  folding  of  leaves  of  sensiOve  plant,  Mimosa  

•  Fast:  Venus  fly  trap  

Venus  fly  trap  

Physiology:  gefng  and  using  energy  

•  All  living  things  require  energy  to  maintain  life  •  Energy  released  by  metabolism  of  food  (sugar,  etc.)  

•  Green  plants  make,  then  use,  their  own  food  •  Plants  without  chlorophyll  (such  as  parasites  like  Indian  pipe)  must  acquire  and  digest  food  

•  Animals  acquire  and  digest  food  

Photosynthesis  requires  chlorophyll  (green)  and  many  

enzymes  

 Plant  and  animal  respiraOon  same  basic  process,  including  enzymes:  sugar  +  oxygenà  CO2  +  H2O+  

energy  (ATP)    

•  Chlorophyll  can  trap  sun’s  energy,  and  convert  it  to  chemical  energy,  which  then  through  complex  chemical  processes  uses  that  energy  to  build  sugar  molecules  out  of  carbon  dioxide  and  water.  Enzymes  required.  

•  Burning  sugar  to  release  its  energy  requires  complex  chemical  processes  that  pick  apart  sugar,  releasing  energy  stored  in  its  chemical  bonds,  and  used  to  make  ATP.  ATP  provides  energy  for  cell  processes  

Nutrient  procurement:    Mycorrhizae  

•  “Fungal  roots”  associate  with  plant  roots  for  symbiosis:  exchange  of  nutrients  and  food  

PLANT  GROWTH  

•  Meristems:  source  of  new  cells  for  plant;  somewhat  like  stem  cells  in  animals  

•  Apical  stem  and  root  meristem:  primary  growth  

•  In  woody  plants  also  vascular  cambium  (xylem  and  phloem)  and  cork  cambium  (bark):  secondary  growth  

PLANT  HORMONES  

•  Regulators  of  growth  •  Small  quanOOes,  but  large  impact  (as  in  animals)  

•  Tropisms  (Auxins):  response  to  light,  gravity,  touch  

•  Gibberellic  acid:  also  growth  

PHLOEM  AND  XYLEM  

•  Transport  structures  in  vascular  plants  •  Xylem:  dead  cells:  water  transport  from  roots  to  stems  and  leaves  

•  Phloem:  living  cells  transport  sugars  throughout  the  plant  from  leaves  

•  Water  conservaOon:  stomata  open  and  close  

POLLINATION  

•  Wind:  no  flower  petals  needed:  many  trees,  some  herbaceous  plants  (Ragweed!)  

•  Animals:  usually  have  petals  – Call  aienOon  to  flower  for  reproducOon  – Bright  colors:  “come  and  get  it”  – Reward  for  pollinators:  nectar,  pollen  

SEED  DISPERSAL  

•  CONTAIN  FOOD  AND  EMBRYO  •  Move  offspring  away  from  parent  •  Wind:  light  seeds,  usually  associated  with  structure  to  aid  wind:  orchids,  composites  

•  Animals:  cling  to  fur,  fruit  to  eat  •  Explosive  dispersal:  Touch-­‐me-­‐not/jewel  weed  

DANDELION  SEEDS  BLOWIN’  IN  THE  WIND  

Explosive  seed  dispersal:    Jewel  weed/touch-­‐me-­‐not  

Hitchhiker  seeds  

CURRENT  ISSUES  WITH    PLANTS  

•  Habitat  destrucOon:  huge  areas  paved  or  degraded  

•  Invasive  alien  plants  and  animals:  killing  and  damaging  individual  naOve  plants,  landscape  scale  

•  Pollinator  declines,  especially  insect  pollinators  

•  Over  collecOon:  ginseng,  black  cohosh,  orchids,  etc.