how do you put plants in families? how do you know that wheat and sugar cane are both grasses when neither of them

Question: how do you put plants in families? how do you know that wheat and sugar cane are both grasses when neither of them look like grass
- Keywords:
  biology,
  family,
  how science works
Asked by wookiee to Izzy, Amelia on 20 Mar 2014.
- Isabel Webb answered on 20 Mar 2014:
  
  Plants are grouped into families due to having similar characteristics. They might have similar shaped leaves or fruits, or possibly grow in a similar way – like lots of branching or tall stems. Usually many similar features are used to then recognise a family.
  
  It does get complicated though and sometimes we aren’t sure. Now that we can look at DNA, we can trace back which plants are actually related.
  
  Did you know potatoes and tomatoes are in the same family? It means you can ‘graft’ the shoot of a tomato with the root of a potato to make a “tomtato”. Google it – they look cool!

Question: how do you put plants in families? how do you know that wheat and sugar cane are both grasses when neither of them look like grass