Am. J. Bot. Li-Cor Advertisement
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (14)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.
Agricola
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.
(American Journal of Botany. 1999;86:457-464.)
© 1999 Botanical Society of America, Inc.

Sem studies on vessels in ferns. 12. Marattiaceae, with comments on vessel patterns in eusporangiate ferns1

Sherwin Carlquist2 and Edward L. Schneider

Santa Barbara Botanic Garden, 1212 Mission Canyon Road, Santa Barbara, California 93105

Received for publication June 4, 1998. Accepted for publication October 8, 1998.


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION AND CONCLUSIONS
 LITERATURE CITED
 
Scanning electron microscopy (SEM) of tracheary elements of roots of five species from four genera of Marattiaceae and of the rhizome of one species revealed vessel elements present in all. The secondary wall framework of perforation plates is the same as that of lateral wall pitting for vessel elements in all species. Thus, no specialization is present in perforation plates of Marattiaceae compared to the simplified morphology of perforation plates of some leptosporangiate ferns (e.g., Dryopteridaceae, Polypodiaceae, and Pteridaceae). The difference between lateral wall pitting and perforation plates in tracheary elements of Marattiaceae cannot be seen by light microscopy (in which pit membranes are transparent), but is evident with SEM. Diversity in structure of perforation plates (especially the alternation of wide and narrow perforations within a plate) and presence of web-like pit membrane remnants are evident. Vessels are widespread in both leptosporangiate and eusporangiate ferns, although specialization in perforation plates (e.g., bars few and more widely spaced in lateral wall pitting of a given vessel element) is to be expected only in ferns of habitats with marked fluctuation in water availability. Vessels of Marattiaceae lack such specializations and are thus are correlated with the mesic habitats characteristic for the family.

Key Words: eusporangiate ferns • Marattiaceae • perforation plates • tracheary elements • vessel evolution • xylem


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION AND CONCLUSIONS
 LITERATURE CITED
 
In our scanning electron microscopy (SEM) studies on vessel occurrence in ferns, we began with representatives of families that are phylogenetically specialized according to traditional criteria (Tryon and Tryon, 1982 ) or molecular data (Pryer, Smith, and Skog, 1995 ). These genera include Polystichum of the Aspidiaceae (Schneider and Carlquist, 1997 ); Woodsia of the Dryopteridaceae (Carlquist, Schneider, and Yatskievych, 1997 ; Carlquist and Schneider, 1998a ; Schneider and Carlquist, 1998a ); Microgramma and Phlebodium of the Polypodiaceae (Schneider and Carlquist, 1997 , 1998b ); and Astrolepis, Platyzoma, and Pteridium of the Pteridaceae (Carlquist and Schneider, 1997a , b ; Carlquist, Schneider, and Kenneally, in press ). These genera tend to occur in localities that are seasonally dry or cold and have brief periods when water is abundantly available; most notable in this respect are the two epiphytes (Microgramma and Phlebodium). Two specialized fern genera (Phlebodium and Woodsia) were mentioned by White (1962) as likely to have vessels, although light microscopy at that time could not confirm absence of pit membranes on end walls. Pteridium has long been thought to have vessels (see White, 1962 ; Carlquist and Schneider, 1997a ).

The genera listed above all show with light microscopy differentiation between end walls and lateral walls of tracheary elements. End walls in these genera have, as SEM study has confirmed, narrow bars separating perforations that are wide compared with the pits on lateral walls. The perforation plates thus differ from pitted lateral walls not only in the absence of pit membranes, but in the secondary wall frameworks of the perforation plates.

Because all of the genera in the abovementioned families proved to have vessels (with some perforation plates on lateral walls as well as on end walls), we extended our survey of ferns for vessel presence. We selected families of leptosporangiate ferns that are considered to be more primitive on the basis of morphology (Tryon and Tryon, 1982 ) and molecular studies (Pryer, Smith, and Skog, 1995 ). These families include Gleicheniaceae (Schneider and Carlquist, 1998c ), Osmundaceae, and Schizaeaceae (Carlquist and Schneider, 1998b ). In these three families, the secondary wall framework of vessels as seen with a light microscope gives no indication that perforation plates are present, because all walls are alike with respect to the secondary wall framework. However, when viewed with SEM, tracheary elements in these families proved to have perforation plates as judged by absence of pit membranes.

Thus, we observed vessels in both roots and stems of all of the families of leptosporangiate ferns we studied, both primitive and specialized, regardless of whether their habitats were highly seasonal or relatively uniformly mesic. We have now extended our studies into eusporangiate ferns. The primitive status of these families within ferns (Tryon and Tryon, 1982 ; Pryer, Smith, and Skog, 1995 ) is significant, because if vessels are present in eusporangiate ferns, vessels are present in ferns at all phylogenetic levels. We have demonstrated vessels in Ophioglossum (Schneider and Carlquist, in press ), although the work of Morrow (1997) on Botrychium, using transmission electron microscopy, suggests that Botrychium, which is unusual among ferns in having circular bordered pits with tori in tracheary elements, lacks perforation plates. In addition to Ophioglossaceae, the other family generally included among eusporangiate ferns is Marattiaceae. Therefore, with Marattiaceae, our SEM studies of tracheary elements have traversed ferns, admittedly in a sparse fashion. More importantly, our studies have shown diversity in vessel construction in ferns, and very likely further aspects of morphological variations remain to be discovered. Particular genera or families of ferns may have special types of vessels. Our study of Marattiaceae is thus one of numerous contributions to an understanding of vessel diversity in ferns.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION AND CONCLUSIONS
 LITERATURE CITED
 
The specimens studied were preserved in 50% aqueous ethanol and are as follows: Angiopteris evecta Hoffm., cultivated in the greenhouses, University of California, Santa Barbara; Danaea elliptica Sm., El Yunque, Puerto Rico, Dennis W. Stevenson, January 1997; D. wendlandii Reichb. f., Panama, Dennis W. Stevenson 1137 (NY); Macroglossum smithii (Racib.) D. H. Campbell, cultivated at the University of California Botanic Garden, Berkeley, from a collection made on Penrissen Road, 27 km from Kuching, Sarawak, Malaysia, D. Walker s.n.; Marattia fraxinea Sm., cultivated at the University of California Botanic Garden, Berkeley, from a collection made below White Rock Peak, Redlynch Intake Road, Cairns, Queensland, G. Daniels 1 December 1964.

Rhizomes were available only for Danaea wendlandii; for this and for all other species, roots were available. Because roots branching from stem vascular tissue are embedded in stem parenchyma, care was taken in D. wendlandii stems to extract only stem vascular tissue from the rhizomes. Macerations were prepared using Jeffrey's Fluid and stored in 50% ethanol. Macerated portions judged to contain tracheary elements were spread onto aluminum stubs, dried on a warming table, sputter coated, and examined with a Bausch and Lomb Nanolab SEM. Illustrations of the genera and species studied are arranged alphabetically. Although we note features seen in particular species, our observations are not extensive enough to permit us to say whether any particular character state is restricted to a given species.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION AND CONCLUSIONS
 LITERATURE CITED
 
In Angiopteris evecta roots, long scalariform perforation plates are present on tracheary elements (Fig. 1, right two-thirds; Fig. 2, right). The perforation plates are like pitted lateral walls in secondary wall framework (Fig. 1, left; Fig. 2, left) except that perforation plates are devoid of pit membranes. In some perforation plates wide perforations alternate with narrow pits; the narrow pits (mere lines midway between the perforations in Fig. 3) are so narrow they are devoid of pit membranes. Perforation plates bear few pit membrane remnants (Figs. 1–3). We did not see any of the "obscalariform" pitting (pits elongate parallel to long axis of tracheary element) reported on Angiopteris tracheary elements by Bierhorst (1960) , but that configuration is probably a very unusual and aberrant one.



View larger version (147K):
[in this window]
[in a new window]
  		Figs. 1–3. Vessel elements of Angiopteris evecta roots. 1. Tips of two vessel elements. Perforations are mostly devoid of pit membrane remnants. Left facet of vessel at left consists of lateral wall pitting. 2. Portions of two vessels. Vessel at left shows two facets that bear pitting, whereas the vessel at right shows a perforation plate portion with numerous slender bars (many bent due to handling). 3. Perforation plate portion in which perforations alternate with pits so narrow that pit membranes are absent, and the pits appear merely as faint lines. Scales in all figures = 5 µm.

 
Roots of Danaea elliptica have vessel elements that show perforation plates similar to pitted lateral walls except for absence of pit membranes (Figs. 4–9). Pit membrane remnants were visible in perforation plates only in the narrow perforations in those perforation plates in which wide and narrow perforations alternate (Fig. 6). We observed perforations that are unusually wide axially, that is, parallel to the long axis of the tracheary element (Figs. 4, 5, 9). Perforations may have nontransverse orientation of bars of secondary wall material (Fig. 7). Lateral walls are much like those observed in other ferns (pit membranes markedly striate in Fig. 8). Lump-like or cushion-like structures were observed on the outside surfaces of vessels (Figs. 4, 5, 7, 9). These structures are at the cell angles; the perforation plate in Fig. 7 is concave (owing to some collapse related to preparation) and thus the cushions point inward rather than outward. We believe thet these cushions may correspond to the segments of primary wall underlying bars of secondary wall material drawn for Angiopteris evecta by Bierhorst (1960) . Bierhorst terms what may be an expression of this phenomenon as a "primary ridge" and likens it to Bars of Sanio in gymnosperm woods. The fact that Bierhorst terms this a "ridge" instead of a series of cushions (see Figs. 4, 5, 7, 9) may correlate with our observations of the outer surfaces of macerated tracheary elements in three dimensions seen with SEM. Bierhorst (1960) was working with sectioned material observed by means of light microscopy.



View larger version (157K):
[in this window]
[in a new window]
  		Figs. 4–9. Vessel elements of roots of Danaea elliptica. 4. End of a vessel element, showing scalariform perforation plate. 5. Perforation plate portion flanked on either side by a row of cushion-like structures. 6. Perforation plate portion with alternating wide and narrow perforations. The narrow perforations (or pits) contain pit membrane remnants. 7. Portion of a perforation plate, concave because of processing. On left and right edges of the plate are rows of cushion-like or peg-like wall structures. 8. Portion of a lateral wall, with broad striate pit membranes. 9. Perforation plate with bars relatively widely spaced; at left, a series of cushion-like wall structures (one indicated by arrow). Scales in all figures = 5 µm.

 
Roots of Danaea wendlandii have tracheary elements with scalariform perforation plates much like areas of lateral walls except for absence of pit membranes on the perforation plates. For example, in the long slender tip shown in Fig. 10, the left facet is a portion of a long perforation plate, whereas the facet at the right is a lateral wall with membranes in all but a few pits. In Fig. 12, the perforation plate (left) may have a few remnants of pit membranes, but the adjacent face (Fig. 12, right) is clearly a lateral wall with intact pit membranes. Pit membrane remnants were observed in relatively narrow pits intercalated into perforation plates with at least moderately wide perforations (Fig. 11, left; Fig. 12, left; Figs. 13, 15). The porose nature of pit membrane remnants in perforation plates is illustrated in Figs. 15–16. Facets of vessel elements that bear perforation plates are common (Fig. 14). Because of the great length of tracheary elements and because tracheary elements often do not separate in macerations of Marattiaceae, we cannot designate with certainty how many end wall facets are perforation plates. A few tracheary element facets in Danaea wendlandii have a small number of pits, restricted to a portion of the facet (Fig. 11, right). Such sparsely pitted walls may face fibers, sieve cells, or parenchyma cells rather than other tracheary elements.



View larger version (148K):
[in this window]
[in a new window]
  		Figs. 10–14.  Vessel elements of roots of Danaea wendlandii. 10. Long, slender tip of vessel element; the left facet is a perforation plate; the right facet consists mostly of lateral wall pitting. 11. Perforation plate (left), and on facet at right, sparsely distributed oval pits. 12. Facets of two adjacent vessel elements; the facet at left is a perforation plate, whereas the facet at right consists of lateral wall pitting that resembles the perforation plate except for presence of pit membranes. 13. Perforation plate with marked differences in sizes of perforations; narrower perforations (or pits) contain pit membrane remnants (arrows). 14. Facets of two adjacent vessel elements; the two facets at right are probably perforation plates, but the plates are interrupted by occasional pits. Scales in all figures = 5 µm.

 


View larger version (148K):
[in this window]
[in a new window]
  		Figs. 15–18.  Tracheary elements of Danaea wendlandii. Vessel elements of roots (Figs. 15–16, long axes arranged vertically) and rhizomes (Figs. 17–18, long axes arranged horizontally). 15. Perforation plate with alternating wide and narrow perforations; the latter contain pit membrane remnants (one indicated by arrow). 16. Perforation plate with perforations of relatively uniform size. Web-like pit membrane remnants are present in three of the perforations. 17. Perforation plates of adjacent vessels and, at top, a lateral wall in which a few pores are evident in pit membranes. 18. Portions of perforation plates, with strands of primary wall material seen in perforation in background (arrow, lower left). Scales in all figures = 5 µm.

 
Rhizomes of Danaea wendlandii have vessel elements much like those of the root (Figs. 17, 18). A few pores in pit membranes may be seen (Fig. 17, top; Fig. 18, top). Some strands of primary wall material are present in perforations (Fig. 18, arrow at lower left).

Tracheary elements of roots of Macroglossum smithii (Figs. 19–21) have oval to elliptical perforations. Perforations nearly circular in shape are shown for the tip of a tracheary element in Fig. 19; two pits are illustrated in the lateral wall subtending the perforation plate (Fig. 19, bottom). At least two perforation plates are shown for the tracheary elements of Fig. 20; the cell facet at far right is a lateral wall with pit membranes mostly intact. In some perforation plates of Macroglossum smithii, pit membrane remnants are present. Some of these pit membrane remnants are notably web-like or porose (Fig. 21).



View larger version (155K):
[in this window]
[in a new window]
  		Figs. 19–23. Vessel element portions from roots of Macroglossum smithii (Figs. 19–21) and Marattia fraxinea (Figs. 22–23). 19. Perforation plate near tip of vessel element. Perforations are wide with two pits below perforation plate. 20. Perforation plates of three superimposed vessel elements, showing elliptical to rectangular perforations and, at right, a facet that bears lateral wall pitting. 21. Four porose pit membranes from transition between pitting and perforations at end of a perforation plate. 22. Perforation plate clear of pit membranes at left; facet at right contains some strands of primary wall material. 23. Two adjacent vessel elements; all facets appear to be perforation plates, although pit membrane remnants are present in some of the perforations. Scales in all figures = 5 µm.

 
In roots of Marattia fraxinea, perforation plates are very long, and adjacent facets of a particular tracheary element may be perforation plates. This is particularly clear in the two tracheary elements of Fig. 23. Some pit membrane remnants are present in vessels of this species, but one can easily find perforations devoid of any pit membrane remnants (Fig. 22, left).


   DISCUSSION AND CONCLUSIONS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION AND CONCLUSIONS
LITERATURE CITED
 
All of the species of Marattiaceae studied have vessel elements in roots; vessel elements were observed in the rhizome of the one species for which rhizome material was available. Perforation plates are very long. Adjacent facets of a particular tracheary elements may bear perforation plates, but because we could not see the entirety of a tracheary element, we could not clearly discern whether perforation plates of an element may occur on both end walls and lateral walls. We can affirm that, as with other fern families we have studied, perforation plates in Marattiaceae can occur on more than a single end wall facet at each end of a tracheary element. This is in contrast with the pattern observed in angiosperms, in which a vessel element is observed with few exceptions to have a single perforation plate at either end. The perforation plates of Marattiaceae are interrupted occasionally by one or more pits. Alternating wide and narrow perforations (the latter often with pit membrane remnants) are also characteristic of several species studied; these have been observed in other ferns (e.g., Phlebodium: Schneider and Carlquist, 1997 ). No tracheids were observed with certainty in Marattiaceae.

Tyloses are reported to be common in protoxylem and metaxylem of three genera of Marattiaceae (McNicol, 1908 ). This tends to confirm that vessels are present in Marattiaceae, because tyloses in vascular plants are virtually unknown in cells other than vessel elements (Zürcher, Kucera, and Bosshard, 1985 ).

The nature of the cushion-like structures on the outer surfaces of and near the angles of tracheary elements of Marattiaceae (seen clearly in Danaea elliptica) is in need of further exploration.

The secondary wall framework of tracheary elements of Marattiaceae reveals no differentiation between walls bearing pit membranes and walls that are perforation plates. Thus, pit membrane presence and thereby presence and extent of perforation plates can be demonstrated in Marattiaceae only with electron microscopy. The similarity of perforation plates to lateral walls bearing pits suggests that if high rates of flow per unit time are a selective factor for simplification of perforation plates (e.g., wide and few perforations per perforation plate, as in Woodsia ilvensis), conductive rates are slow and steady in Marattiaceae. Marattiaceae are uniformly characteristic of wet forest understory (e.g., Tryon and Tryon, 1982 ). Ferns in which there is clear differentiation in secondary wall framework between a perforation plate and a lateral wall bearing pits (e.g., Aspidiaceae, Dryopteridaceae, Polypodiaceae, Pteridaceae) are characteristic of sites where water availability fluctuates markedly with season, whether by virtue of freezing, summer drought, or with periods of rainfall in the case of species with epiphytic habit, as summarized in the next paragraph.

Lack of differentiation of perforation plates from pit-bearing lateral walls also characterizes tracheary elements of Ophioglossum (Schneider and Carlquist, in press ) as well as genera from the putatively primitive leptosporangiate fern families Gleicheniaceae, Osmundaceae, and Schizaeaceae (Schneider and Carlquist, 1998c ; Carlquist and Schneider, 1998b ). Is this lack of differentiation a primitive condition, or is it correlated with restriction of these ferns to mesic situations? Our data suggest that well-differentiated perforation plates in ferns such as Astrolepis, Marsilea, Phlebodium, Pteridium, and Woodsia are correlated with marked extremes in water availability. Woodsia is instructive in that W. obtusa (Spreng.) Torr. has little differentiation in morphology between perforation plates and lateral wall pitting (Carlquist, Schneider, and Yatskievych, 1997 ), and this is also true of the majority of species studied by means of light microscopy by White (1962) . However, two species, W. scopulina D. C. Eaton (Schneider and Carlquist, 1998b ) and W. ilvensis (L.) R. Br. (Carlquist and Schneider, 1998 ), have perforation plates different from lateral wall pitting. The most logical explanation of this pattern is that in these two species of Woodsia, there is relatively high selective pressure for a perforation plate configuration that will transmit more water per unit time during the brief periods of water availability. Both of these species of Woodsia occupy areas where winter freezing and summer drought abbreviate the growing season, and therefore vessels that supply water rapidly are of value. The more primitive families of ferns, such as Marattiaceae, typically occur in mesic sites, so we conclude that perforation plates much like the pitting on tracheary elements in these species suffice to meet the relatively slow and steady conductive rates in these habitats.

At this point in our survey of tracheary tissue in ferns, we conclude that vessels are widespread both in leptosporangiate ferns and in eusporangiate ferns. In future studies on fern tracheary tissue, we will focus on the correlation between perforation plate morphology and climatic extremes. We are exploring ferns of aquatic habitats and ferns of desert localities.


   FOOTNOTES
 
1 Back

2 Author for correspondence. Back


   LITERATURE CITED
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION AND CONCLUSIONS
 LITERATURE CITED
 
Bierhorst, D. W. 1960 Observations on tracheary elements. Phytomorphology 10: 249–305.

Carlquist, S., and E. L. Schneider. 1997a SEM studies on vessels in ferns. 2 Pteridium. American Journal of Botany 84: 581–587.

———, and ———. 1997b SEM studies on vessels in ferns. 4 Astrolepis. American Fern Journal 87: 43–50.

———, and ———. 1998a SEM studies on vessels in ferns. 6 Woodsia ilvensis. Flora 193: 179–185.

———, and ———. 1998b SEM studies on vessels in ferns. 10. Selected Osmundaceae and Schizaeaceae. International Journal of Plant Sciences 159: 788–797.[CrossRef]

———, ———, and K. F. Kenneally. In press SEM studies on vessels in ferns. 8. Platyzoma. Australian Journal of Botany.

———, ———, and G. Yatskievych. 1997 SEM studies on vessels in ferns. 1 Woodsia obtusa. American Fern Journal 87: 1–8.

McNicol, M. 1908 On cavity parenchyma and tyloses in ferns. Annals of Botany 22: 401–413.

Morrow, A. C. 1997 Investigation of the intertracheid pit membranes of the woody fern Botrychium. Ph.D. dissertation, Auburn University, AL.

Pryer, K. M., A. R. Smith, and J. E. Skog. 1995 Phylogenetic relationships of extant ferns based on evidence from morphology and rbcL sequences. American Fern Journal 85: 205–282.[CrossRef][ISI]

Schneider, E. L., and S. Carlquist. 1997 SEM studies on vessels in ferns. 3. Phlebodium and Polystichum. International Journal of Plant Sciences 158: 343–349.

———, and ———. 1998a SEM studies on vessels in ferns. 5 Woodsia scopulina. American Fern Journal 88: 17–23.

———, and ———. 1998b SEM studies on vessels in ferns. 7 Microgramma nitida. Anales de Biología, ser. Botánica 69: 1–7.

———, and ———. 1998c SEM studies on vessels in ferns. 9 Dicranopteris (Gleicheniaceae) and vessel patterns in leptosporangiate ferns. American Journal of Botany 85: 1028–1032.[Abstract]

———, and ———. In press SEM studies on vessels in ferns. 11 Ophioglossum. Botanical Journal of the Linnean Society.

Tryon, R. M., and A. F. Tryon. 1982 Ferns and allied plants, with special reference to tropical America. Springer Verlag, New York, NY.

White, R. A. 1962 A comparative study of the tracheary elements of the ferns. Ph.D. dissertation, University of Michigan, Ann Arbor, MI.

Zürcher, E., L. J. Kucera, and H. H. Bosshard. 1985 Bildung und Morphologie der Thyllen. Eine Literaturübersicht. Vierteljahrschrift Naturforschung Gesellschaft Zürich 130: 311–333.




This article has been cited by other articles:


Home page
 Am. J. Bot.Home page
J. S. Sperry, U. G. Hacke, and J. Pittermann
Size and function in conifer tracheids and angiosperm vessels
Am. J. Botany, October 1, 2006; 93(10): 1490 - 1500.
[Abstract] [Full Text] [PDF]

Home page
 ANN BOT (LOND)Home page
S. E. SCHECKLER and J. GALTIER
Tyloses and Ecophysiology of the Early Carboniferous Progymnosperm Tree Protopitys buchiana
Ann. Bot., May 1, 2003; 91(6): 739 - 747.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Bot.Home page
S. Carlquist and E. L. Schneider
Vessels in ferns: structural, ecological, and evolutionary significance
Am. J. Botany, January 1, 2001; 88(1): 1 - 13.
[Abstract] [Full Text]

Home page
 Plant Cell PhysiolHome page
J. Nakashima, K. Takabe, M. Fujita, and H. Fukuda
Autolysis during In Vitro Tracheary Element Differentiation: Formation and Location of the Perforation
Plant Cell Physiol., November 1, 2000; 41(11): 1267 - 1271.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Bot.Home page
E. L. Schneider and S. Carlquist
SEM studies on vessels in ferns. 17. Psilotaceae
Am. J. Botany, February 1, 2000; 87(2): 176 - 181.
[Abstract] [Full Text]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (14)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.
Agricola
Right arrow Articles by Carlquist, S.
Right arrow Articles by Schneider, E. L.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS