Exam 3 Flashcards
Vascular cambium
produces part of the secondary body of the plant: the secondary xylem (wood) and the secondary phloem (part of the bark - the corkcambium produces the rest of the bark)
Cambium
a sheetlike fundamental type of meristem. The vascular cambium produces secondary xylem and phloem; the cork cambium (phellogen) produces the cork tissue of the bark. Both cambia are considered to produce secondary tissues.
Cambial region
a term that is usually employed to designate a cambium and the most recently produced derivatives
Biseriate cambium
a theory that the vascular cambium consists of two parallel layers of cells, one producing the secondary xylem, the other producing the secondary phloem
Uniseriate cambium
theory that the vascular cambium consists of one layer that is able to produce both xylem and phloem
Bifacial
derivatives produced in both directions in uniseriate cambium
Fusiform initials
cells of the vascular cambium that produce axially elongated or oriented elements of the wood or inner bark
Ray initials
cells of the vascular cambium that produce the radially oriented rays
Proliferative divisions
when fusiform initials divide with longitudinal, periclinal walls to produce new derivatives
Multiplicative divisions
when fusiform initials divide with anticlinal, longitudinal walls to produce more initials rather than derivatives
Nonstoried cambium
vascular cambium in which the fusiform initials are not aligned with each other as they are in a storied cambium, where the ends of one fusiform initial are even with those around it
Storied cambium
fusiform intials are aligned with each other laterally and form stories or tiers, rare and only occurs in some advanced dicots
Stratified cambia
another name for storied cambia
Nonstratified cambia
another name for nonstoried cambia
Pseudotransverse divisions
divisions that start out with the appearance of a longtitudinal division, but the phragmoplast and cell plate do not reach the far ends of the cell
Domain
all the fusiforms in a large region
Declining initial
a fusiform initial that becomes progressively shorter and is finally converted to a ray initial or is expelled from the cambium
Declining tier
– a row of axial cells in the secondary xylem or phloem that are progressively shorter because the fusiform initial is itself becoming shorter
Fasicular vascular cambium
this structure develops in a portion of each strand in the procambium in plants that will become woody
Aggregate rays
a mixture of fusiform initials, uniseriate ray initials, and multiseriate ray intials that have the appearance of a large ray
Interfascicular vascular cambium
cambium that develops between the vascular bundles
Annual rings
annual increments resulting from the periodic activity of the vascular cambium
Sapwood
the outer, conducting layers
Heartwood
inner, nonconducting rings
Tyloses
first means of blocking a vessel that is formed when a living parenchyma cell pushes part of its wall and cytoplasm through a pit into the lumen of the vessel
Gummosis
the second method of blocking a vessel; paratracheal parenchyma cells produce gums that flow through the pits and fill the lumen
Homocellular rays/homogenous
conifer rays consisting of parenchyma cells only
Ray tracheid
special cell accompanying parenchyma in conifer ray
Heterocellular rays/erogenous
conifer ray with ray tracheid and parenchyma cells
Crossfield pitting
pitting that interconnects rays with the axial system
Fenestriform pit
when a pit chamber is very wide so there is only enough space available for one pit in the cell wall
Primary rays
rays initiated by cells of the interfasicular region or the procambium
Secondary rays
rays which have their origin in the conversion of fusiform initials to ray initials in the vascular cambium
Softwood
wood lacking libriform fibers, containing on tracheids
Spring wood/early wood
wood formed when growing conditions are ideal that contains wide and relatively thin walled tracheids
Summer wood/late wood
wood produced later in the season that contains narrow, thick walled tracheids to provide extra strength and reduce risk of cavitation
Growth ring bridges
bordered pit-pairs on tangential walls found in cells at the boundary between the late wood of one year and the early wood of the subsequent year
Crassulae
prominent dark bands above and below most circular-bordered pits of tracheids in all conifers except the Araucariaceae
Bars of Sanio
another word for crassulae
Pycnoxylic wood
wood that contains very little parenchyma, either axial or ray parenchyma
Manoxylic wood
wood containing very large amounts of parenchyma, characteristic of cycads and some advanced dicots
Upright cells
specialized ray parenchyma cells with an upright shape that facilitate transfers between radial and axial conducting systems
Procumbent cells
wider cells that facilitate transfer between radial and axial conducting systems
Primitively vesselless
wood of primitive dicots that retains many gymnosperm features, primarily the absence of vessels
Secondarily veselless
small number of species that has “lost” vessels
Ring Porous
wood in which the springwood contains very large vessels and distinct rings are easily visible
Diffuse porous
wood with vessels occuring more uniformly through the annual ring
Hardwood
dicot wood with fibers
solitary
vessels that don’t occur in clusters
multiples
vessels that are grouped together
Paratracheal parenchyma
parenchyma cells immediately adjacent to the vessels
Apotracheal parenchyma
parenchyma cells scattered among the fibers and tracheids
Diffuse parenchyma
if the apotracheal parenchyma cells occur as idioblasts or as isolated uniseriate strands
Banded/metatracheal parenchyma
if Apotracheal parenchyma form large clusters or bands
Initial parenchyma
if there’s a concentration of apotracheal parenchyma at the inner boundary of the annual ring
Terminal parenchyma
if there’s a concentration of apotracheal parenchyma located at the outer boundary of the annual ring
Scanty paratracheal parenchyma
if paratracheal parenchyma doesn’t form a complete sheath around the vessel
Unilaterally paratracheal parenchyma
if located on one side of the vessels
Vasicentric parenchyma
surrounds vessels completely
Aliform parenchyma
if the parenchyma of one group of vessels is not confluent with the parenchyma of other vessels
Confluent parenchyma
if several vessel clusters lie within a single large band of parenchyma
Air seeding
drawing air bubble into a vessel
Septate fibers
undergo normal growth except stay alive and undergo several subdivisions
Compression wood
when reaction wood forms on the lower side of the branch where the tissues are compressed
tension wood
when reaction wood forms on the upper side
gelatinous fibers
found in reaction wood of dicots
g-layer (gelatinous layer)
contains more cellulose but small amt of lignin
compact tension wood
when gelatinous fibers occur clustered together
diffuse tension wood
when gelatinous fibers occur side by side or in small groups
Cauliflorous
They produce flowers on older branches or the trunk. Thier flowers and fruits are major sinks and may require large-volume transport through the secondary phloem
Primary Sclereids
sclereids that differentiate and mature at the same time as the other cells
Secondary Sclereids
sclereids that appear only later, arising after conduction has stopped
Dilatation
The circumferential expansion of the secondary phloem that allows it to avoid being torn apart by the accumulation of secondary xylem interior to it.
Dilatation Tissue
The formation of dilatation tissue effects dilatation
Prolifertive Tissue
A type of dilatation tissue formed by cell division in the axial parenchyma of the secondary phloem.
Expansion Tissue
A type of dilatation tissue formed by cell division in the phloem rays
Periderm
The technical term for bark; the periderm contains the cork (phellem) that is produced by the cork cambium (phellogen) and any epidermis, cortex, and promary or secondary phloem that might be exterior to the cork cambium.
Phellogen/Cork Cambium
The cork cambium of the bark. The phellogen contains only cuboidal or short columnar cells, it usually produces only cork (phellem) to it’s exterior, but in some species it also produces a small amount of parenchyma (phelloderm) to its interior.
Phellem (Cork Cells)
Cork, specifically the rather large amounts produced by a phellogen. The individual cork cells that occur in grass leaves are never considered phellem
Bark
The layers of secondary phloem and periderm on stems, roots, and rarely leaves
Lenticels
A region in the bark that allows the diffusion of oxygen into the plant.
Inner Bark
The layers of living tissue in the bark, located between the vascular cambium and the innermost cork cambium.
Outer Bark/Rhytidome
The outer, dead portions of the bark, located to the exterior of the innermost cork cambium.
Phelloderm
Small amounts of parenchyma cells produced on the inner side
Phelloid
A thin-walled cell, that wasn’t converted to phellum, located among the cork cells of phellem.
Suberin Layer
A layer of the hydrophobic material, suberin, on the inner surface of a cell wall; this is found in cork cells.
Closing Layer
A layer of cork cells firmly attached to each other; located in a lenticel.
Storied Cork
A type of periderm formed by the limited cell division of cortical parenchyma cells, with little or no expansion of the daughter cells.
Wound Periderm
The layers of cork cells that are induced to form when most plant tissues are cut or otherwise damaged.
Common Type
Fossil groups and some extant genera that do have vascular cambia and secondary growth that differ significantly from what can be termed the common type.
Bidirectional Cambium
The common type of cambium that produces secondary xylem to one side and secondary phloem to the other
Continuous Cambium
The common type of cambium that continues to function for the entire life of the plant.
Successive Cambium
The cambia that function for a limited time.
Included Phloem
Any secondary ploem that is located interior to secondary xylem.
Conjunctive Tissue
The pithlike tissue that forms the matrix surrounding the vascular bundles of a monocot root or stem.
Secondary Cortex
Formed when the surrounding tissues become quiescent and the cambium finally becomes distinct it is located centrally, forms newly produced parenchyma on the outside
Secondary Bundles
contains only tracheids, not vessel elements
Sporophyte
generation in the life cycle of plants that produces the spores
Gametophyte
generation in the life cycle of plants that produces the gametes
Spores
single cells that function in reproduction by germinating and growing into a new plant, the gametophyte; in all vascular plants spores are produced by meiosis and are haploid
Alternation of Heteromorphic Generations
alternation of generations in which the diploid generation is easily distinguishable from the haploid generation
Microgametes
smaller of the gametes in oogamy; often called a sperm cell
Megagametes
larger of the gametes in oogamy; often called an egg cell
Zygote
the cell that is produced after an egg is fertilized (diploid)
Microgametophyte
a gametophyte (haploid plant) that produces the microgametes (sperm cells)
Megagametophyte
a gametophyte (haploid plant) that produces the megagametes (egg cells)
Microspores
- in plant species with heterosporous reproduction, the smaller spore type; microspores germinate and grow to become microgametophytes
Megaspores
in plant species with heterosporous reproduction, the larger spore type; megaspores germinate and grow to be megagametophytes
Archesporial Cells
a cell in a sporangium that is reputed to be the initial for the formation of all the spore mother cells and some of the surrounding sterile cell layers
Primary Sporogenous Layer
the layer of cells that are produced by division of the archesporial cell
Endothecium
in microsporophylls the hypodermal layers formed by the primary wall layer
Tapetum
inner most layer of sterile cells that surrounds the sporogenous tissue in a microsporophyll
Integument
a jacket of cells that covers the central mass of cells in an ovule
Nucellus
the central mass of cells in an ovule
Chalaza
the basal portion of the nucellus, the point at which it attaches to its stalk
Micropyle
the small hole in the integument at the apex of an ovule through which pollen or pollen tubes enter
Generative Cell
in a pollen grain or pollen tube, the cell that will divide to produce two sperm cells
Filament
the stalk of a stamen
Anther
portion of the stamen that contains the sporogenous tissue and surrounding sterile tissues
Pariental Tapetum
a tapetum in whcih the cells remain on the periphery of the anther loculus
. Invasive Tapetum
a tapetum in which the walls break down and the tapetal protoplasts surround the microspore mother cells
Periplasmodium
the large mass of fused tapetal protoplasts that form around the developing pollen grains in an anther that has an invasive tapetum
Pollinium
all the pollen grains of an anther sac of orchids stick together, forming a pollinium
Massula
all the pollen grains of an anther sac of milkweed stick together, forming a massula
Intine
the innermost wall of a spore or pollen grain.
Extine
the outermost wall of a spore or pollen grain.
Stigma
the uppermost portion of a carpel that receives pollen grains
Style
the portion of a carpel between the stigma and the ovary; elevates the stigma to a position that facilitates pollination
Ovary
lower most portion of the carpel that contains the ovules and develops into the fruit
Transmitting Tissue
tissue in the style through which pollen tubes grow
Pseudosyncarpous Styles
a compound style in which each component style still has its own region of transmitting tissue
Eusyncarpous Styles
a compound style in which the component styles are completely fused together and only one mass of transmitting tissue is present
Placenta
regions of a carpel where the ovules are attached
Funiculus
stalk of an ovule
Atropus (orthotropous)
an ovule that is straight, not bent, such that the micropyle is directed away from the funiculus
