Hydrophytes Flashcards
why verythin/no waxy cuticle
don’t need to conserve water as plenty available so water lost by transpiration not an issue
why lots stomata always open
-maximises gas exchange.
- No risk plant loosing turgidity as always water
-If floating leaves eg lilies need stomata on upper surface so in contact with air
why reduced structure
water supports leaves and flowers so doesn’t need strong support structure
why wide flat leaves
to spread across water surface to capture max light
why small roots
as water can diffuse directly into stem and leaf tissue so less need for roots
why large SA of stem/root underwater
maximises area for photosynthesis and oxygen to diffuse into submerged plants
why air sacs
enables leaves or flower to float on water surface
what is aerenchyma?
specialised parenchyma that forms in leaves/stems/roots. Lots air spaces formed partly by apoptosis (programmed cell death) in normal parenchyma
why need aerenchyma?
-leaves and stems more buoyant
-Forms low resistance internal pathway for movement substances such as oxygen to tissues below water
- helps with anoxic conditions in mud by transporting 02 to tissues
-often in crops like rice plants
what issues with aerenchyma found?
provides low resistance pathway for methane produced by rice plants to atmosphere.
Issues as contributes to greenhouse effect therefore impacting climate change .
mangrove adaption?
root waterlogged so air low
aerial roots grow called pneumatophores which grow up into air
lenticles allow air enter woody tissue
