Lecture 5 Flashcards
- Name the major plant organs
The major organs of vascular plants
are sporophytic roots and shoots
- What are the continuously actively dividing cell regions of a plant called and where are they
located
Apical meristem: actively
dividing cells of the shoot
What is meant by plant habit and what are the types of plant habit?
CAAFS P CRD
* Defines relative position of the
stem or shoot, but may also be
based on stem structure,
growth, and orientation
* Caulescent: plant with an
above-ground stem
* Acaulescent: lacks an above-
ground stem, leaves are
born at ground level
Stems and shoots: growth habit
* Arborescent: treelike in
appearance and size
* Frutescent: shrub, with
numerous, woody, aerial
trunks
* Suffrutescent: basally woody
and herbaceous apically -
* Prostrate: trailing or lying flat,
not rooting at the nodes
* Repent: creeping or lying flat
but rooting at the nodes
* Decumbent: being basally
prostrate but apically
ascending
* Cespitose: multiple aerial but
short-stemmed shoots arise
from the base, forming a
much-branched cushion e.g.,
many grasses
Name various types of plant habitat
five major habitats are – forests, grasslands, deserts, mountains and polar regions, and aquatic habitat
- What is the function of roots?
Typically function in anchorage and
absorption of water and minerals
What are the root cap, root hair, adventitious root, and lateral root?
Apical meristem gives rise to the protective root cap
Root hairs: great increase in surface area
Roots from a nonroot organ (stem or leaf) are
adventitious roots
Roots arising from other roots are lateral roots
- What is the difference between a taproot and a fibrous root system?
Taproot system: primary root is dominant
Fibrous system: primary root withers and disappears
What is a shoot
Shoot: stem + associated leaves
- What is a bud, where do buds typically develop, and what do they develop in?
Buds: immature shoot systems
- from meristematic regions
Apical meristem and leaf axils
- Define node, internode
Nodes are points of attachment for leaves, aerial roots, and flowers. The stem region between two nodes is called an internode
- What is the difference between a bulb, corm, and tuber?
- Bulb: shoot consists of a small
amount of vertical stem tissue
(roots below) and a massive
quantity of thick fleshy storage
leaves - Corm: underground shoot,
stem tissue surrounded by
scanty, scale-like leaves (e.g.,
some Iris spp., irises) - Tuber: thick, underground
storage stem, usually not
upright, typically bearing outer
buds and lacking surrounding
storage leaves or protective
scales (e.g., Solanum
tuberosum, potato)
What is the difference between a caudiciform stem and a pachycaul?
Caudiciform stem: low, swollen, perennial storage stem (at or above-ground level), from which arise annual or nonpersistent photosynthetic shoots (e.g., Calibanus, some Dioscorea spp.)
* Pachycaul: woody, trunklike stem that is swollen basally, the swollen region functioning in storage (e.g., bottle trees, Brachychiton spp., and the boojum tree, Fouquieria columnaris)
What is thorn and how does it differ from a spine or prickle?
- Thorn: woody, modified stem
- Spine: modified leaf/stipule
Define: tiller, burl, pseudobulb, short shoot, tendril
- Tillers: branches that develop from leaf axils at each unelongated node of the main shoot or from other tillers
- Burl: made up of a tree’s bud tissue- knobby growth
- Pseudobulb: bulbous enlargement of the stem
- Short-shoots, sometimes called “spurs,” are reproductive shoots
- Tendril is a specialized stem, leaf or petiole with a threadlike shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as Cuscuta
Name the difference between acaulescent and caulescent; between prostrate, repent, and
decumbent.
- Caulescent: plant with an
above-ground stem - Acaulescent: lacks an above-
ground stem, other than the
inflorescence axis –
photosynthetic leaves are
born at ground level - Prostrate: trailing or lying flat,
not rooting at the nodes - Repent: creeping or lying flat
but rooting at the nodes - Decumbent: being basally
prostrate but apically
ascending
What is the difference between monopodial and sympodial?
Monopodial: stem axis is
derived from growth of a
single apical meristem
* Sympodial: axis (which may
appear to be a single,
continuous structure) made
up of numerous units, derived
from separate apical
meristems – may appear to be
a single continuous structure
Draw a typical twig and label terminal bud, axillary bud, leaf scar, vascular bundle scars, lenticels.
see phone
What is the difference between an axillary, terminal, and pseudoterminal bud? a collateral and
superposed bud
- Apical (or terminal) bud: bud
of a twig that contains the
original apical meristem of the
shoot (which by later growth
may result in further extension
of the shoot) - Lateral (or axillary) bud:
formed in the axils of leaves - Pseudoterminal bud: the
original terminal apical
meristem of a shoot aborts
(e.g., by ceasing growth or
maturing into a flower), then
an axillary bud near the shoot
apex may continue extension
growth - axillary bud that
assumes the function of a
terminal bud - Collateral buds: two or more
axillary buds that oriented
sideways - Superposed buds: two or more
axillary buds oriented
vertically
difference between a rhizome, caudex, and stolon
(runner)?
rhizome: rootstock with a horizontal, underground stem with short internodes
caudex: undifferentiated vertical stem- swollen axis of a woody plant
stolon: stem with long internodes that runs on or just below the surface of the ground, generally terminating in a new plantlet
