2. What are Angiosperms???
• The flowering
plants (angiosperms), also
known
as Angiospermae or Magnolio
phyta, are the most diverse group
of land plants. Angiosperms
are seed-producing plants .
3. Parts Of Angiosperms
• The parts of an Angiosperm include:
• Roots, which are generally underground and serve to absorb
water and nutrients
• Stems, which come in various types such as:
– stolon, an above-ground “runner”
– rhizome, an underground “runner”
– bulb, a fleshy stem modified for nutrient storage
• Leaves, which can be either simple or compound in form
and which alternate with each other going up the stem or
can be arranged opposite each other on the stem or
as whorled leaves where more than two originate from the
same place on the stem
4. Characteristics Of Angiosperms
• Despite their diversity, angiosperms are clearly united by
a suite of synapomorphies (i.e., shared, derived
features) including:
• 1) ovules that are enclosed within a carpel, that is, a
structure that is made up of an ovary, which encloses the
ovules, and the stigma, a structure where pollen
germination takes place,
• 2) double fertilization, which leads to the formation of an
endosperm (a nutritive tissue within the seed that feeds
the developing plant embryo),
• 3) stamens with two pairs of pollen sacs,
• 4) features of gametophyte structure and development,
and
• 5) phloem tissue composed of sieve tubes and
companion cells
6. Cotyledons
• Plant embryos in seeds have structures
called cotyledons. Cotyledons are called
‘seed leaves’ because in many instances
they emerge and become green when the
seed germinates.
7. Division Of Angiosperms
• The angiosperms are divided into two
groups on the basis of the number of
cotyledons present in the seed .
• Plants with seeds having a single
cotyledon are called monocotyledonous or
monocots
• Plants with seed having two cotyledons
are called dicots.
