स्वयम् on its own, निपतितैः fallen down, कुसुमसङ्घातैः bunches of flowers, शयनप्रस्तरैरिव like a bedstone, उपस्तीर्णा scattered, इयम् this, भूमिः ground, सुखाकृता rendered comfortable.

'With countless flowers fallen on their own from trees and scattered like a bed of flowers on stone the ground is rendered comfortable enough to relax on.