Stem Tendril

• Sweet peas climb with tendrils.Jupiterimages/Photos.com/Getty Images
  
  Vines are plants that cannot reach favorable heights to achieve sunlight without help. The thin, herbaceous stems cannot support their weight, and therefore tendrils evolved as a way to overcome this lack of strength. Tendrils are modified short stems that arise from axillary buds. Axillary buds are located in the axle at the base of the leaf. Tendrils can coil around small objects with which they come in contact. Once the plant has anchored itself, it will grow upward a short distance before sending out more tendrils to support itself.
  
  

Stem Thorn

• Bougainvillea has thorns that arise from axillary buds.Jupiterimages/Photos.com/Getty Images
  
  Thorns are hard, straight structures that are modified stems. Spines and prickles differ in that they are modified leaves. Thorns can arise from axillary or terminal buds, or buds that are found on the end of the branches. Some plants, such as pomegranate, produce leaves, flowers and fruit on the thorn. Thorns play a key role in checking the transpiration rate, or how much a plant is using water. Thorns also help to ward off grazing herbivores and unsuspecting gardeners with pruners in hand.
  
  

Phylloclade

• The flattened stems with clusters of spines can be seen on this opuntia cacti.Jupiterimages/Photos.com/Getty Images
  
  Phylloclade can be seen in cacti species as flattened stems of several internodes, the segment of a stem between two nodes, or growing points. This flattened stem acts as a leaf, on which many develop a cluster of spines that arise out of the axillary buds. These spines check the rate of transpiration and prevent herbivores from eating them. On some cacti, phylloclade do not form spines, but rather small leaves or scales.
  
  

Cladodes and Cladophylls

• Cladodes of a cacti can produce flowers and fruit.Brand X Pictures/Brand X Pictures/Getty Images
  
  Cladodes are the flat, leaf-like modified stems that can be found in cacti and other species. Cladodes look remarkably like leaves, but you can identify a leaf from a cladode by what may be growing on a cladode. Because cladodes are stems, they can have flowers and fruit growing from them. You will not see a flower growing directly from a true leaf. Cladophylls can be found on asparagus, and arise from axillary buds by minute, bract-like true leaves.
  
  

Bulbil

• Bulbils are modified floral buds that are designed for reproduction. The multicellular body grows from the axillary bud in Dioscorea. The bulbil detaches from the plant, lands on the ground and begins forming a new, independent plant. If you have ever grown garlic, you may have noticed small bulbils forming in the round flower head at the top of the stalk. These bulbils are a means of propagation.