Plastids:
Plastids are a group of organelles found in plant cells. They all have thier own genetic material which is inherited independently from the DNA in the cell nucleus, and they are surrounded by a double membrane.
The most common plastids are chloroplasts which contain the green pigment chlorophyll. There are also chromoplasts which contain carotene pigments and which are responsible for the yellow, orange and red coloration in flowers and fruits. Leucoplasts occur in plant tissues that do not turn green - a common form, the amyloplast, is used to store starch. A specialized form of amyloplasts, the statoliths, are present in root and shoot tips and are involved with the way the plant responds to gravity.