Download Lesson Plan 2a

HortBotany
Lesson Plan #2a
Plant Classification
Angiosperms
 There are over 250,000 species of angiosperms. Angiosperms are
flowering plants. They make up around 80 percent of all the living
plant species on Earth.
http://www.biology.iastate.edu/Courses/211L/Anthoph/%20AnthophINDX
 They produce true flowers.
 Flowers: are reproductive structures.
 The parts of an Angiosperm flower:
PETAL
RECEPTACLE
SEPAL
PEDICEL
STIGMA
ANTHER
STYLE
STAMEN
PISTIL
OVARY
FILAMENT
OVULE
 Angiosperm Development
 Ovules are borne within an enclosed structure called the ovary.
Fertilized ovules develop into “seeds”. After fertilization the ovary
begins to swell and eventually becomes a fruit. The ovules that were
once enclosed by an ovary have become seeds which are now
enclosed by a swollen ovary or fruit. A cucumber is technically a
fruit, in the botanical sense, even though we call it a vegetable. Maple
schizocarps, Oak acorns, pumpkins, tomatoes, eggplant and cherries
are also all fruits. How do you know? If you cut them open they
contain seeds.
 Definition of a “fruit”: in a botanical sense, a fruit is a swollen ovary
containing seeds.
 Angiosperms are divided into two important Classes
 Monocots & Dicots
Number of
Cotyledons
Dicots
Monocots
TWO
ONE
Venation
NETTED
Flower Parts
4’s or 5’s
Vascular
Bundles
ARRANGED IN
A RING
AROUND THE
PITH
PARALLEL
3’s
SCATTERED
Seeds:
Seeds have 3 basic parts:
1)
Embryo + cotyledon(s)
2)
Seed Coat
3)
Food Storage
SEED COAT
ENDOSPERM
(FOOD STORAGE)
ONE COTYLEDON
EMBRYO
Monocot
Seed
SEED COAT
TWO COTYLEDONS
(FOOD STORAGE)
EMBRYO
Dicot
Seed
Gymnosperms (Cycadophyta, Ginkgophyta, Gnetophyta and Coniferophyta)
 The word gymnosperm means: “naked seed”.
 Seeds are not surrounded by an ovary.
 The Gymnosperms that we are most familiar with are the Conifers
(cone bearing plants).
 The conifers include such plants as: Pine, Fir, Spruce, Hemlock,
Douglas-fir, Larch, Juniper, etc.
 Most conifers are: evergreen. Evergreen species retain their foliage
year-round.
 In conifers, seeds are borne on the scales of female cones. Pollen is
produced in separate male cones borne at the ends of the branches.
Generally speaking, the scales of the female cones are hard and
woody. However, some species produce female cones with soft, fleshy
scales like those found in the Junipers (Juniperus).
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