Funeral Traditions vary for each culture and faith. There are a few general guidelines to help. If there is any doubt it is also a good idea to check with local religious leaders or family members.
Catholic
Flowers are usually welcomed and appreciated. For deliveries to the church, you should confirm details with the Parish, as practices may vary in regard to where and how flowers may be displayed etc.
Other Christian Faiths
Floral expressions of all kinds are generally welcome at funerals and memorial services. Of course, individual churches may have their own limitations on placement. Flowers sent to the family home are often very welcome for those who are unable to attend the funeral service.
Church of Jesus Christ of Latter Day Saints, the Mormans
Most floral tributes are encouraged and appropriate, except flowers arranged on a cross or crucifix. Funerals are not normally held inside the temple.
Eastern Orthodox
During the period before burial (three days after death), flowers may be sent to the funeral home. There is often an emphasis on white flowers. Some placement restrictions may apply. Those unable to attend the funeral may send flowers to the funeral home or the family home.
Hindu
Hindu custom is to try and hold a service at a funeral home before the sun goes down on the day of the death. Flowers generally may be sent, although doing so isn't necessarily part of the Hindu tradition. Garlands and mixed seasonal sprays of flowers are typical.
Islamic
Opinion varies as to the appropriateness of sending flowers. Some say the islamic emphasis on simplicity makes gifts of flowers unsuitable, others say sending flowers is appropriate. Seek the opinion of a local religious leader or the family. If flowers are appropriate, Roses and other fragrant varieties are especially popular, Palm branches, other greens, or individual flowers are also often placed on the grave.
Jewish
Sending flowers to a funeral home or burial site is not normally done. Instead, fruit and food baskets are traditionally sent to the home during the mourning period. Increasingly, however, friends are choosing to send flowers to bereaved family members at home following the funeral. Similarly, it's becoming more common to see some floral decorations sent to adorn the synagogue foyer. These newer traditions however are generally not practiced among Orthodox Jews.
Buddhist
Most Buddhist funerals take place in a funeral home - not in a temple. Sending flowers is normally considered appropriate.