Plant Cells, Tissues, & Meristems - Millersville University Herbarium
Introduction to Botany. Lecture 33Secondary stem Wood Monocot “wood” Most of monocots do not...
Transcript of Introduction to Botany. Lecture 33Secondary stem Wood Monocot “wood” Most of monocots do not...
Introduction to Botany. Lecture 33
Alexey Shipunov
Minot State University
November 27, 2013
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 1 / 39
Outline
1 Questions and answers
2 Secondary stemWoodLife forms
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 2 / 39
Outline
1 Questions and answers
2 Secondary stemWoodLife forms
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 2 / 39
Questions and answers
Previous final question: the answer
Where is a cambium?
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 3 / 39
Questions and answers
Previous final question: the answer
Where is a cambium?
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 3 / 39
Questions and answers
Previous final question: the answer
Where is a cambium?
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 3 / 39
Secondary stem Wood
Secondary stemWood
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 4 / 39
Secondary stem Wood
Primary and secondary stems (scheme)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 5 / 39
Secondary stem Wood
How cambium works
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 6 / 39
Secondary stem Wood
Secondary structure of stem (photo and explanations)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 7 / 39
Secondary stem Wood
Secondary xylem and rays
Secondary xylem, or wood, is the product of vascular cambiumSome cambium cells are fusiform initials; they form axial vesselelementsOther cambium cells are ray initials; they form rays (parenchyma+ tracheids)Rays provide horizontal transport of water; axial system providevertical transport
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 8 / 39
Secondary stem Wood
Fusiform and ray initials
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 9 / 39
Secondary stem Wood
Three planes of view
Transverse (cross-section)Radial (longitudinal section from center to periphery andperpendicular to stem surface)Tangential (longitudinal section parallel to stem surface)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 10 / 39
Secondary stem Wood
Three plains of maple (Acer sp.) wood
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 11 / 39
Secondary stem Wood
Three plains again (the scheme)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 12 / 39
Secondary stem Wood
Earlywood and latewood
Earlywood (springwood) contains more parenchyma and oftenhave larger vessel elementsLatewood (summerwood) often have small vessel elements andlooks darker
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 13 / 39
Secondary stem Wood
Diffuse and ring porous wood
In ring porous wood (like in red oak) bigger vessel elementsconcentrate in earlywoodIn diffuse porous wood larger vessel elements spread acrossearly- and latewood (American elm)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 14 / 39
Secondary stem Wood
Diffuse and ring porous wood in two species ofcinquefoil (Potentilla spp.)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 15 / 39
Secondary stem Wood
Annual rings
Interleaving early- and latewood from to sequential years form animpression of annual ring“Ring” is just a layer of darker (i.e., smaller) cellsTropical trees do not form annual rings
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 16 / 39
Secondary stem Wood
Annual rings in juniper (Juniperus sp.)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 17 / 39
Secondary stem Wood
Sapwood and heartwood
Sapwood is a peripheral layer of working xylem, it usually hasrelatively light colorHeartwood is a central, non-functional, old, dark-colored xylem
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 18 / 39
Secondary stem Wood
Sapwood and heartwood of European pine (Pinussylvestris)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 19 / 39
Secondary stem Wood
Tyloses
Tyloses control the winter functioning of vessels
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 20 / 39
Secondary stem Wood
Conifer wood
Simpler structure, few cell typesSimple raysSometimes have resin ducts; resin secreted by epithelial cells
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 21 / 39
Secondary stem Wood
Ginkgo (Ginkgo biloba) wood (not a conifer, butgymnosperm)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 22 / 39
Secondary stem Wood
Resin duct in pine wood ( c©BSA)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 23 / 39
Secondary stem Wood
Monocot “wood”
Most of monocots do not have lateral meristems and thereforehave no true woodPalms have only primary tissues; their trunk widens from bottomto topSome monocots (dragon trees) have anomalous secondarygrowth
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 24 / 39
Secondary stem Wood
Cross section of palm (Phoenix canariensis) trunk
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 25 / 39
Secondary stem Wood
Dragon tree (Dracaena draco) and its anomalouscambium
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 26 / 39
Secondary stem Wood
Anomalous secondary growth in Bougainvillea(Bougainvillea spectabilis)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 27 / 39
Secondary stem Life forms
Secondary stemLife forms
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 28 / 39
Secondary stem Life forms
Life forms
It is a different view on the plant diversityLife forms represent different lifestylesFor example, trees, shrubs and herbs are life forms
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 29 / 39
Secondary stem Life forms
Life forms: dynamic approach
Hardiness: sensitivity to all negative influenceWoodiness: % of cells with secondary wallsSlenderness: proportion of vertically ordered stems
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 30 / 39
Secondary stem Life forms
Life form cube
��
��
��
���
��
��
��
���
��
��
��
���
~
~ ~
~
~
~ ~
~
��������3
-
Hardiness
Slenderness
Woodiness
1
5
6 8
7
42
6
2
3
#1 could be similar to duckweed, #8—to sequoia
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 31 / 39
Secondary stem Life forms
Life forms: Raunkiaer’s approach
Phanerophytes: winter buds openly exposedChamaephytes: winter buds under snowHemicryptophytes: winter buds on soil surfaceCryptophytes: winter buds in the soilTherophytes: no winter buds, only seeds
The Raunkiaer system is very useful to characterize the whole floras,especially temperate floras
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 32 / 39
Secondary stem Life forms
Raunkiaer classification (after Raunkiaer, 1937)
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 33 / 39
Secondary stem Life forms
Raunkiaer classification again
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 34 / 39
Secondary stem Life forms
Life forms: architectural models
Developed for tropical trees, but also cover temperate forms whichare less diverseEach model has a name of famous botanist, e.g. Thomlinson,Cook, AttimsBased on the character of branching, development of generativeshoots, directions of growing
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 35 / 39
Secondary stem Life forms
Example of architectural model: Attims
Many temperate trees are growing according to this model
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 36 / 39
Secondary stem Life forms
Final question (2 points)
Please describe the difference(s) between heartwood and sapwood
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 37 / 39
Secondary stem Life forms
Final question (2 points)
Please describe the difference(s) between heartwood and sapwood
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 37 / 39
Secondary stem Life forms
Summary
Wood is a secondary xylemLife forms represent different “life styles” of plant
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 38 / 39
Secondary stem Life forms
For Further Reading
A. Shipunov.Introduction to Botany [Electronic resource].2010—onwards.Mode of access:http://ashipunov.info/shipunov/school/biol_154
Th. L. Rost, M. G. Barbour, C. R. Stocking, T. M. Murphy.Plant Biology. 2nd edition.Thomson Brooks/Cole, 2006.Chapter 5.
Shipunov (MSU) Introduction to Botany. Lecture 33 November 27, 2013 39 / 39