Plant Image Collection

Xylem DevelopmentActions


04-001h Quick view

Section through xylem region of a vascular bundle drawn from electron micrographs. Parenchyma cells present; all other cells are tracheary elements in various developmental stages. Scale line, 10 um.

04-002h Quick view

Ontogenetic sequence of primary xylem elements (from bottom to top) with annular secondary wall thickenings (rings) gradating to helical thickenings in a moderately stretched cell.

04-003h Quick view

Side wall between two differentiating vessel members. Fibrous material is present in vesicles connected with the near wall. Middle lamella and connections between microtubules and plasmalemma.

04-004h Quick view

Side wall between differentiating vessel members. Secondary wall deposition not yet evident. In the older cell (below), microtubules concentrate near young helical thickenings and are absent along the primary wall.

04-005h Quick view

Side wall between vessel members with differentiating helical thickenings. More mature cell (right) indicated by larger amount of secondary wall deposition. Vesicles between plasmalemma and secondary wall are evident.

04-006h Quick view

Wall between older (right) and younger (left) vessel members. Microtubules accumulate near the secondary wall in younger cell. Membrane-bound vesicles appear as blebs on plasmalemma. Primary wall of older cell are partly hydrolyzed.

04-007h Quick view

Vessel member above, parenchyma cell below. Primary wall is partly hydrolyzed in the vessel member. Protoplasmic residue covers the secondary and hydrolyzed primary wall.

04-008h Quick view

Degradation of primary wall of vessenl member is almost complete. Primary wall of other cell is partly hydrolyzed between the coils of the helix. Older helix subjected to greater amount of stretching.

04-009h Quick view

Later stage of end wall degradation.

04-010h Quick view

Rim of secondary wall material (top) has been deposited around the margin of the end wall delimiting the future perforation. Part of the end wall not covered by the rim (bottom) has been removed.

04-011h Quick view

Vesicles occur near the surface of the exposed wall part and some also within the immature rim. Microtubules near the rim at arrowheads.

04-012h Quick view

Nucleus in a xylem parenchyma cell. At cw, primary cell wall between two parenchyma cells.

04-013h Quick view

Protoplast of differentiating vessel member with part of end wall. Details in the protoplast include dictyosome with vesicles, mitochondria, microbodies, rough and smooth ER, and autophagic vacuoles.

25-001 Quick view

Habit view of Psilotum sporophyte

25-002 Quick view

Close-up view of fertile branch

25-003 Quick view

Psilotum aerial stem, transverse section (x.s.)

25-004 Quick view

Psilotum aerial stem free-hand section, phloroglucinol + HCL staining

25-005 Quick view

Close-up of stele showing fibers in

25-006 Quick view

Psilotum stem x.s.

25-007 Quick view

Psilotum synangium l.s.; sporocyte stage; note wispy tapetum, multiple layers of eusporangium wall, foliar appendage

25-008 Quick view

Psilotum synangium l.s. higher magnification; sporocytes prior to completion of meiosis

25-009 Quick view

Psilotum gametophyte with anheridium and archegonium; endophytic fungus present in ground tissue of gametophyte

25-010 Quick view


25-011 Quick view

Tmesipteris aerial stem x.s.; siphonostele, mesarch primary xylem; locate proto- and metaxylem

25-012 Quick view

Tmesipteris synangium x.s. pre-meiosis stage; note multiple wall layers

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Creation and update

Created by admin on Oct 23, 2013
Last update
Updated by admin on Oct 23, 2013

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