Lecture 7 Flashcards
Flowers structure
- Cortex : group of sepals
- Corolla: group of petals
( Perianth Undifferentiated cortex and Corolla ) - Androecium : male organ form of stamens (anther filament)
4.gynaecium : female organ formed of carpels (stigma , style , ovary )
Bract
Leave have flower or group of flowers in its axil
Involucre
group of bracts arranged in 1-2 whorls just bellow flower
Pedicel
Flower stalk (pedicellate or sessile)
Types of symmetry of all leaves
Actinomorphic : can be divided by a number of cuts into equal halves (>1 plane of symmetry)
Zygomorphic : divide into two equal halves
Asymmetric : can’t divide equally
Hermaphrodite
Perfect
Bisexual
Sterile
Natural both organs absent
Perianth
The outer flora parts when they are not differential into clyx and corolla
If thin green = sepaloid perianth
If thin colored= petaloid perianth
Calyx function , separate, united
Protection of other organs
S = Polysepalous
U= Gamosepalous
Corolla function
Attraction for pollination
Protection of sexual organs
Inner surface is usually papillosed for adhesion pollen grain
Why Corolla is colored ?
Due to anthocyanins (colored change with PH) also Due to flavones and carotenoid
Androecium cohesion of stament
Epipetalous: stament appear inserted upon the Corolla
Syngenesious: filaments are free but anthers are compositae
Monadelphous: anthers are free but filaments are compositae
Pollen grains shapes
Triagonal, Hexagonal,Spiny ,Smooth, Spherical
Pollen grains show 2 layers
Extine: outer thick layer showing 1-3 pores (from which pollen grains tube protrudes)
Intine: inner delicate layer
Gynaecium shape
Simple (1) = monocarpous
Free (>1) = apocarpous
United (>1) = syncarpous
How many ovules in ovary
1 or more ovules arranged on the placenta
Flora parts insertion
Hypogynous ( No hypanthium )
Epigynous (hypanthium present)
Perigynous (Hypanthium present)
Inflorescence types
Racemose
Cymose
Compositae flowers
Daisy or Asteraceae
What characteristic of family Asteraceae?
Capitulum or flower head
Very short swollen axis either conical or flattened carrying sessile florets
Types of florets in capitulum
Ray florets : starp-shaped Corolla
Disc florets: tubular corrola
Disc florets only in…
Santonica
Ray florets only in……
Dandeline
Ray floret (ligulate) 6
1.Zygomorphic
2. Pistillate
3. Sessile
4. Calyx present or absent
5. Corrola 3 gamopetalous, white, epigynous
6. Androecium absent
Ray floret (ligulate) 6
Zygomorphic
Pistillate
Sessile
Calyx present or absent
Corrola 3 gamopetalous, white, epigynous
Androecium absent
Disc floret 6
- Actinomorphic
- Bisexual
- Sessile
- Calyx present or absent
5 . Corolla 5 gamopetalous, yellow, epigynous - Androecium 5 syngenesious epipetalous
