Flower-Offering as Worship
Arcana (worship through offering, especially flowers) is the primary mode of archa-avatāra worship. In its most common form, it involves offering flowers (one by one or in garlands) to the deity while reciting the Lord's names — each flower accompanied by a name, so that a sahasranāmārcana (worship with the thousand names) involves one thousand flower-offerings while reciting each of the thousand names.
The Nāma as Essential
Arcana is essentially an act of nāmārcana — the name and the offering together form the complete act. The flower alone is insufficient; the name must accompany it. This reflects the theological principle that the Lord's name and the Lord Himself are non-different — the name has the same transformative power as the Lord's presence.
Forms of Arcana
Arcana ranges from simple home worship (offering a few flowers daily from the home garden while reciting names) to elaborate temple arcana with hundreds of flowers during major festivals. The Pañcarātra ritual texts specify different flowers for different deities, times, and purposes — but the underlying principle of loving personal attention remains constant.
Prapatti and Arcana
For the prapanna, arcana is continued as kaiṅkarya — not as a means of accumulating merit but as a natural expression of love. Nammāzhvār and other Āzhvārs describe their mental arcana — offering flowers of devotion from the garden of the mind — as the highest form of this service. Āṇḍāḷ's Tiruppāvai describes the gopīs' flower offerings as a model of arcana motivated purely by love.