Lecture 5 Flashcards
What are leaves
Lateral outgrowth on the stem normally of limited growth function mainly as a food factory
Types of leaves (5)
Floral leaves
Cotyledon leaves (seed leaves)
Scale leaves
Bract
Foliage
Floral leaves
Include sepale , petals, stamens and carpels (No buds in their axils)
Cotyledon leaves
Supply nutrition for plants embryo to generate
Bract
Leaves have flower or group of flowers in their axils
Foliage leaves
Ordinary green leaves Normal leaf function (photosynthesis )
Scale leaves
Thin , membranous No chlorophyll (don’t do photosynthesis)
Protect buds and store water
Types of foliage leaves
- Opposite
- Opposite decussate or spiral (2 opposite leaves perpendicular to the pair above and below)
- Alternate (1leaf in each node)
- Whorled (2 leaves or more at each node)
Stipulate
Like Small thorn grow for protection of young axillary bud
Stem without stipulate called exstipulate
Types of foliage leaves (petiolate)
Petiolate
Sessile
Pulvunis (petiolate with small swollen sac of water in its end)
Leaf shape (mention three)
ovate
Cordate
Linear
Lenceolate
Oblong
Leaf apex
Acute
Spiny
Rounded
Emarginate
Leaf margin
Smooth - entire
Dentate
Lobed
Lamina base
Symmetric
Asymmetric
Leaf histology
Study of leaf tissue under microscope
What is stomata
Modified epidermal cells
Function : exchange gases and transportation
Stomata
Osteol (pore or stoma)
Guard cells
Accessory cells (cells surround the guard cells)
* number of stomata in lower surface is larger than number of stomata in upper surface )
Types of stomata
Paracytic
Diacytic
Anomocytic
Anisocytic
Anther name for Hairs is ……………
Trichomes
Hairs function
Key role in plant protection
Types of trichomes
Non glandular
Glandular (have the ability to store natural products (essential oils ) )
Senna trichomes
Non glandular unicellular curved (bent hair ) covered with warty ceutical
Chemical test for senna
Borntrager’s test (test for free anthraquinone)
Modified borntrager’s test (test for combined anthraquinone)
Ruthenium Red (test for acidic mucilage )
Senna uses
1.Laxative for constipation
2. Bowel evacuation prior to surgery or x-ray investigation
3. Slimming herbal tea
