the sugarcane is -- Ikshvaku .

Really? Thats interesting. Can you elaborate?

Mallika -- I have no sources to corroborate the claim -- however the sugar cane bow is rarely used aspect of iconography, in context of use with Lord Rama, it should represent his lineage here should it not?

yes you are right Rama belongs to Ishvankyu Dynasty which means sugarcane. Good many such pictures are more near to realities.

It could also be Kama! The god of love is often depicted with a bow made of sugarcane.

Kamadev would normally be depicted fair skinned and without a sword & shield. Rama is described as dark skinned.