Stem function and variation

Stems hold up leaves. Why might that be important to a plant?

 

Stems hold up flowers. Why might that be important to a plant?

 

Stems transport water from the soil to the leaves, and transport sugars from the leaves to the roots (...or [advanced topic alert:] from where they have been stored as starch in a storage organ like a potato or storage root to where they are needed, like regrowing leaves and branches after the winter or after a fire, or after an animal has eaten them.).

Some stems do not grow upright and tall. You can still tell they are stems, instead of roots, because they have nodes with (sometimes tiny) leaves and axillary buds.

Some of these modified stems are underground and horizontal. These types of stems are called rhizomes.

Some of these modified stems are short, fat and underground. These are called tubers. A potato is an example of a tuber.

View a description and drawings of different modified stems at http://theseedsite.co.uk/bulbs.html. Learn these, then complete the activity below.