POLLEN STRUCTURE
Geos/Anth 481/581

Intectate without tectum Magnolia [-]
Tectate with tectum
Simitectate with some tectum, forming a pattern
e.g., Frustulate - Bitterroot Lewisia rediviva

• COSTAE: thickening of inner layer of exine
  
  • transversalis: transverse furrow Umbelliferae [-]
    
  • aequatorialis: thickening continuous, or "ends" of furrow indistinct Ptelea
    
• ANNULUS: thickening of outer layer of exine Gramineae [-]
  
• VESTIBULUM: separation of inner and outer layers of exine Betula [-]
  
• OPERCULUM: exine covering aperture, which can become detached Agave, Simmodsia [-]
  
• MARGO: sculptural or structural feature of exine at aperture other than costa or annulus. examples: thinning of exine, change in reticulation size, abrupt change of wall angle into aperture. Salix, Rosa [-]
  

• FORM (alpha - α)
  
  • Furrow: colpate
    
    1. even with wall
    Cα1a narrow Rumex [-]
    Cα1b wide Acer [-]
    2. protruding or intruding
    Cα2a protruding Canotia [-]
    Cα2b intruding Rosa [-]
    
    
    
  • Furrow: colporate C3(P3)
    
    3. furrow with equatorial feature
    constriction gradual a-c
    Cα3a Cassia
    Cα3b Cercidium [-]
    Cα3c Cornus
    constriction abrupt d-f
    Cα3d Sedum [-]
    Cα3e
    Cα3f
    interrupted g-h
    Cα3g Mentzelia [-]
    Cα3h
    bridged
    Cα3i Forsellesia
    
  • Pore: porate
    
    Pα1 even with wall Urtica
    Pα2 intruding Cannabis [-]
    Pα3 protruding Celtis
    Pα4 vestibulum Betula
    
  • Pore: colporate C3P3
    
    CPαa elongate polar
    CPαb spherical Prosopis
    CPαc elongate equatorially Rhus, Euphorbia [-]
    CPαd double Astragalus
    
  
  
• DELIMITATION (beta - β)
  
  • Furrow or Pore
    
    1 diffuse:
    Cβ1a irregular Menodora
    Cβ1b indistinct Abronia
    
    sharp:
    Cβ2a acute
    Cβ2b rounded
    
    accessory:
    Cβ3a margo Rosa [-]
    Cβ3b costae or annulus Cephalanthus [-]
    
  
  
• STRUCTURE (gamma - γ)
  
  • Furrow or Pore
    
    Cγ1 open or thin
    Cγ2 with exine elients Actea Aquilegia [-]
    Cγ3 operculum Agave
    Pγ3 operculum Gramineae