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
