Botany Vocab

Roots Modifications 

  • Food storage: sweet potato 

  • Prop/ Adventitious roots: support 

    • Adventitious roots “prop roots”: arise from stem or leaf tissue

    • Roots are positively gravitropic

    • Roots are Negatively Phototropism:  

  • Pneumatophores: gas exchange 

    • Black mangrove 

    • The roots are getting oxygen / bc they are heterotrophic 

  • Aerial roots: Valemen of orchid: thick epidermis for water conservation

    • Valemen = multiple epidermis = stores water instead of sugar 

    • Monocot= red pic 

    • Xero plant 

      • Hypodermis 

  • Prop roots: grow from stems: Banyan 

    • Come front he branches and stem? 

  • Prop Roots: grow from stems 

    • Red Mangrove 

    • Salt water environment: Keep salt where it doesn't interfere with the rest of plant 

  • Buttress Roots: stability in shallow soils: fig tree

    • Soil is so porous so this is an adaptation 

  • Hansotia: parasitic roots 

    • Grow on a host plant and suck up the sugar 

    • dodder : yellow bc they aren't doing a lot of photosynthesis so don't need to be green  

  • Mycorrhizae: fungi associated with roots 

      • ON TEST blue around is the ectomycorrhizae, but they can penetrate into the cells → endomycorrhizae  

      • Symbiosis RELATIONSHIP: THE VERY FIRST PLANTS HAD THIS RELATIONSHIP

        • Plant gets more water because there is more SA , osmotic pressure 

        • Plant gets phosphorus from fungi 

        • Fungi receives sugars from plant 

  • Root Nodules: bacteria (Rhizobium): associated with legume (beans)  roots: nitrogen fixation 

    • Bacteria make NH3 and NO3 from N2 for the plant 

    • The nodule provides an anaerobic environment for bacteria 

    • Farmers rotate crops they add beans to get more nitrogen 

      • Next steps = gmo corn to have nodules

Stem Modifications 

  • Rhizome

    • horizontal stems below ground=> adventitious roots(arise from stem or leaf tissue)

  • Runners

    • above ground horizontal stem—long internodes; adventitious roots at alternate nodes; may also have shoots emerge from node

  • Stolon

    • similar to runners w/node-internode anatomy, but occur below ground; Irish potato is at the end of a stolon

  • Tuber

    •  at the end of a stolon, several internodes swell; mature tuber becomes isolated at the end of the stolon; “eyes” are nodes

  • Bulbs

    • large buds surrounded by fleshy leaves ; small stem at the lower end; adventitious roots grow from the lower end

    • Onion 

  • Corms

    •  Mostly fleshy stem surrounded by a few scale-like leaves

    • Ex: radishes 

  • Cladophylls

    • flattened stem with buds and small scale-like leaves

  • Thorns

    • axillary buds form a sharp spine--protection

  • Tendrils

    • modified for clinging to other surfaces while climbing (grapes)