Study Leaves: Lesson 1 - Identify Leaf Types

Leaf varieties by Marco Almbauer.

       Leaves  show  an  almost  infinite  variety  both  of  structure  and  of  shape. They  are  the  breathing  organs  of  the  plant,  and  by  their  aid  the  plant  makes organic  material  from  its inorganic  food.  When  all  the  parts  are  present  a leaf  consists  of  a  blade,  a  leaf-stalk,  and  a sheath  with  stipules.  In  outline  the  blade  shows  every  imaginable  geometric  form  and  is described accordingly.  Those  with  a  notched  instead  of  a  narrow  base  are  described  as heart shaped  (cordate),  kidney-shaped  (reniform),  eared  (auriculate),  arrow-shaped  ( sagittate ),  and spear-shaped  (hastate).  When  the  leaf  is  joined  to the  stalk  by  some  portion  of  its  under surface,  and  not  by  its  bottom  edge,  it is  said  to  be  shield-shaped  (peltate).  Leaves  are  also described  according to  the  character  of  their  top  (apex)  and  of  their  bottom  (base).  If  the blade is  undivided  it  is  said  to  be  entire ;  if  there  be  slight  indentations  on  the margin  the blade is  said  to  be  crenate,  serrate,  or  dentate ;  if  the  indentations  are  considerable  it  is  called incised,  and  if  the  indentations  go  more deeply  still  into  the  green  surface  so  that  the  blade  is divided  into  several parts  it  is  said  to  be  lobed  or  partite.

• This is the first lesson; the second lesson about how leaves function is here. 

Required for Observation: A  number  of  leaves,  of  different  forms - some simple  and  some  compound.  The  leaves  selected  should  also exhibit  different  kinds  of  surface  (rough,  smooth,  hairy,  bright, &c.),  and  a  variety  of  edges  (toothed,  saw-like,  crenate,  spiny,  &c.). The  following  common  leaves  would  make  a  good  selection to collect and show in the classroom: laurel,  nasturtium,  oak,  lilac,  elm,  cuckoo-pint,  dandelion,  horse-chestnut,  rose,  primrose,  wallflower,  iris,  willow,  ground -ivy, ivy,  fir.

Method of Student Observation: 

•  A  typical  leaf,  such  as  that  of  the elm,  lime,  or  beech,  should  be  given to  each  child,  who  should  be  encouraged  to  observe  and  describe  it.
• The  wallflower  leaf  may  be  chosen to  illustrate  the  sessile  leaves,  and  a rose  leaf  to  illustrate  the  compound.
• For  the  observation  a  great  variety  of  leaves should  be  used;  and  each  leaf  should be  examined  and  described  separately  by  the  children.
  

How to Grade Study Notes For Student Journals: Every student will need a journal to write in weekly for this online nature study series. Teacher will assign the weekly content in advance.

• Make sure the facts are: written in complete sentences, the first word of each sentence capitalized, and a period should be included at the end of each sentence.
• Spell check your vocabulary and write the words correctly.
• Dress up your journal entries with student clip art, drawings of your own in color or in black and white.
• Student may also include photographs of their own taking for extra credit.

Look for the following facts about leaves inside of student journals. Assign a point value to the quality of the content.

• General  Description  of  a  Leaf - A  leaf  generally  consists  of  a  stalk ( petiole )  and  a  blade.  The  midrib, running  through  the  center  of  the leaf,  is  usually  continuous  with  the stalk;  and  veins  branch  out  from  it.  Some  leaves  have  no  stalk,  but  sit on  the  stem.  They  are  termed  sessile  leaves. When  a  leaf  is  divided  into  two or  more  parts,  each  of  which  has  its own  stalk,  it  is  called  a  compound leaf. 
• Form  and  Surface  of  Leaves. -Leaves  exhibit  a  great  variety  of form  and  surface. The  principal  forms  are: circular (orbicular),  oval,  ovate,  heart-shaped (cordate),  arrow-shaped  (sagittate), lance-like  (lanceolate),  oblong,  rhomboid,  linear  (long  and  narrow),  angular,  hand-shaped  (palmate),  fingerlike  (digitate). The  edges  may  be  plain,  toothed,
  saw-like  (serrate),  scalloped  (crenate), spiny,  or  deeply  and  irregularly notched. The tip  of  the  leaf  may  be  sharp (acute)  or  blunt  (obtuse).  The  surfaoe,  rough,  smooth,  hairy,  shiny.  

Video at Youtube for Students to Watch:

1. Differences between simple and compound leafs by Kids Cloud - Leaf identified as Palmate versus Pinnate
2. Leaf identified as Phyllotaxy: 5 forms: Alternate, Opposite, Decussate, Whorled and Spiral by sci-ology
3. Learn to recognize different types of leaf shapes by Nature Clearly - basic shapes: elliptic, oval, ovate, oblong, lanceolate, obvovate, linear, reniform, lunate, fiabellate, fan-shaped, subulate, pandurate, pelfate, spathulate, hastate, sagitate, needle shape
4. How are leaf Edges different, Margins: entire, toothed, lobed, ciliate, crenate, dentate, denticulate, doubly serrate, serrate, serrulate, sinuate, spiny, undulate by Compredend & Converse
5. The Longer Tree Identified Lesson Video by Christian Libdan
6. Angie Patterson discusses the identification of trees by looking at leaves by Black Rock Forest
7. Adaxial Surface verses Abaxial Leaf Surface - distinguish the surfaces by Bio Hub

Graphic Organizers To Make: For  the  illustration  of  this  part  of the  lesson  a  great  variety  of  leaves should be used; and  each  leaf  should be  examined  and  described  separately  by  the children.
        Drawings should  also  be  made  of  all  the  principal  forms. After  the  leaves  have  all  been described separately and labeled, they  may  be classified additionally by any of the five following attributes. Choose just one from the five categories for a graphic organizer.

1. according to Palmate or Pinnate - simple and compound
2. according to form or Basic Shapes
3. according to their Edges or Margins
4. Adaxial versus Abaxial according to their surfaces
5. according to Phyllotaxy - growing point of a shoot
   

The leaf art lessons located on my blog here that may be completed for this assignment:

• Create Fall Leaf Patterns - 4th -6th Grade
• Tear and Paste Falling Leaves - preschool
• Craft a Fall Landscape Using Leaf Rubbings - 1rst, 2nd, and 3rd Grade
• Paint, cut and paste a leafy river scene - 1rst, 2nd and 3rd Grade
  

Extended Learning Content: 

• Why Leaves Change Color - article, one of many recommend during seasonal/camp learning at my doll blog
  
• Poison ivy leaves on Looking Glass Lake - part of the story adventures of a nurse paper doll
  

Free Student Clip Art: Clip art may be printed from a home computer, a classroom computer or from a computer at a library and/or a local printing service provider. This may be done from multiple locations as needed because our education blog is online and available to the general public.

Kinds of leaves in the clip art: ground ivy, ivy, dandelion, fir, iris, oak, horse chestnut, elm,
 lilac, laurel, nasturtium, and cuckoo-pint.