CELL TYPE CYTOPLASMIC FEATURES CELL WALL FEATURES 3-D GEOMETRY
Tracheid

Subcategories based on location and geometry
 
Name Location
Axial or Vascular In conducting tissue of secondary xylem
Ray In rays of secondary xylem, often at upper and/or lower margins
Vasicentric Surrounding vessel elements

 Student Image (Pinus)

 No cytoplasm at maturity

Diameter of lumen is about the same as thickness of cell wal

 Uniformly thick secondary cell wall with circular or elliptical bordered pits

Cell Wall / Lumen Ratio about one
Axial or Vascular
Transverse Isodiametric
Longitudinal  Very elongated cylinder with tapered ends
Ray
Transverse Elongated with longest axis in radial plane
Radial Elongated with longest axis in radial plane
Tangential Isodiametric
Vasicentric
Transverse Isodiametric
Radial Elongated with longest axis in convoluted vertical  plane
Tangential Elongated with longest axis in convoluted vertical  plane
 
Fiber-tracheid

Intermediate form between Fiber and Tracheid l

 No cytoplasm at maturity

Diameter of lumen is slightly less than thickness of cell wall

 Uniformly thick secondary cell wall with elongated pit canal that extends slightly beyond a circular pit chamber.

Cell Wall Lumen Ratio slightly larger than one
Transverse Isodiametric
Longitudinal Elongated cylinder with tapered ends