bulbs

ashley13

Hi my name's Ash, im 41 from North Wales.  I am disabled due to a Road Traffic Accident when i was 6 years old.   I've suffered head injury which i had short term memory but as i've gotten older my memory has improved a little.    I work in a garden centre which i find interesting.   My line manager has a mind of information about plants, she amazes me.   She suggested to me last week to look up winter bulbs and learn a little about them which i looked online about and i understood the terms, Tunic which is the outer coat/skin of the bulb, Basal plate which is the flat part at the bottom of the bulb,  but then i can't get my head around scales.   It says online that scales are modified leaves which confuses things more. I can't imagine what modified leaves are.  I thought a bulb was made of dead leaves.  Because of my head injury i find it hard to grasp things which makes learning difficult.   Is there an easier way to explain parts of a bulb?

yorkshirerose

Hello, Ash,

Good question.  The scales are the the part of the bulb which are attached to the root base, but do not grow into leaves or flower shoots.
Their purpose is to store food reserves for the plant to use when required.

I hope this explanation helps you.

Silver surfer

Ash, that is a really hard thing for anyone to understand.
Well done for attempting to get to grips with it.
Maybe this diagram will help.



https://www.bing.com/images/search?view=detailV2&id=10E8BE727B235308024DA25C24209E9ADC931048&thid=OIP.IQKimYBCdnzvVvoUklov3wHaFj&mediaurl=https://www.microscopy-uk.org.uk/mag/imgfeb11/001-hm.jpg&exph=600&expw=800&q=bulb+structure+scales+diagram&selectedindex=33&ajaxhist=0&vt=0&eim=1

Liriodendron

Hello Ash. 

I was going to suggest looking at an onion, as in Silver Surfer's link.  If you cut it in half from top to bottom you can see all those bulb parts you mention - the tunic is the papery skin you take off before you cook it, and the base plate is the bit at the bottom with the roots, which holds the "scales" together.  In an onion, the scales are the bit you eat.  They don't look at all like leaves!  If you keep an onion too long, a green shoot appears from the centre, and the rest of the onion begins to go soft - this is because the shoot is taking food and water from the "scales" around it.

When you plant a flower bulb in compost or in the ground, the roots take up water and food, and the bulb produces leaves and flowers.  But you can tell there's a lot of "food" stored in the bulb because you can grow something like a hyacinth in a special jar with just water. 

https://www.agardenforthehouse.com/wp-content/uploads/2010/09/hyacinths-pictures.jpg

ashley13

Thank you for the information everyone.  Should i think of scales as leaves that hold food instead of calling them modified leaves?  Modified means change so how have leaves changed, how are they different compared with ordinary green leaves on a plant?

Liriodendron

Ash, I guess you know about plants which live longer than a year, storing food to keep them alive through the winter?  With a plant like a paeony, it has swollen roots a bit like potatoes, which store the food made during the summer by the leaves.  

With bulbs, their green leaves also make food while they are growing.  When they die down, the food goes down from the dead leaves into the bulb scales - so yes, you are quite right, the scales could be called "leaves that hold food".  They can't actually make the food, because they are underground, but they are very important for storing the food made by the green leaves, so that the bulb can grow again the next year.  

ashley13

I understand that about bulbs    so instead of defining scales as modified leaves, i can say scales are leaves that hold food?   Can you explain modified leaves please,   when i hear scales being called modified leaves my mind goes blank.   

wild edges

Think of a "leaf" as the green part of the plant that grows above ground and is designed to to capture sunlight. A "modified leaf" would be one that has been changed from this function to serve another purpose for the plant. For example with bulbs the scale is no longer green and grows underground so it is modified to hold food and water rather than sunlight. Another example would be the spines on a cactus. The spines are modified leaves that are now hard and spikey to protect the plant from being eaten.

ashley13

Hi thanks for the threads, very interesting and i do understand the last thread and Lidriodendron's explanation.    I'm making myself a mind map on bulbs,   i've started with,   5 types of bulbs in the centre of the page,  branching out from that is True bulb and branching off that is, Tunic, Scales and Basal plate.    Have i started the mind map ok or can you suggest a better way of creating the mind map so i can remember things easily?   I also want to remember the explanations that you typed.

Dovefromabove

philippa smith2 said:

 An excellent explanation @wild edges

I agree 👍 

I have used a spring onion or leek to help explain ... if you dissect it and peel back the layers you can see where the leaves stop being green here they’ve been above ground and turn white and begin to get fatter below ground where they’re storing the energy. 

wild edges

It might help you to plot a plant's progression from seed to flower. As a broad rule the seed germinates and grows its first leaves, then as it grows through the year it adds more leaves from the basal plate. The base of the leaves below ground modify and swell to form the bulb ready for when the above-ground plant dies back in the autumn. The bulb lies under the soil for the winter as a store of food for next year's plant. In the spring the plant grows up from the centre of the bulb with a new stem and draws the energy from the bulb as it grows until it flowers and makes its own seeds.