Garudapurana 1.197.35

1.197.35

akacaṭatapayaśā vargāḥ pūrvādike nyaset /
patrāntakesarānte tu dvau dvau pūrvādikau tathā //

The consonant classes a, ka, ca, ṭa, ta, pa, ya, and śa he should place beginning in the east; / on the edges of the petals and on the edges of the filaments, two each, beginning in the east likewise;