Anahata, is symbolised by a circular flower with twelve  green petals (According to Wikipedia).

This chakra is the fourth chakra and called the heart chakra  (Anahata). It is related to love, self-acceptance, compassion.  A healthy fourth chakra allows us to love deeply, feel  compassion, have a sense of acceptance socially. A  congested heart chakra can lead to feelings of rejection,  jealousy, loneliness and difficulties in relationships (Debbie Creagh).

This chakra relates to the physical functions of the Thymus Gland, Nerves, Heart, Para sympathetic Involuntary Muscles. Congestion of this chakra therefore can result in problems of  the heart, lungs, breast, arms, asthma, as well as allergies and problems with the immune system (Lee Wei-Dei).

(Citing Siam Reiki materials)