Collared Earth Star

Geastrum triplex

The fruit body is composed of a roughly spherical to egg-shaped structure, the endoperidium, topped by an opening, the ostiole, covered by fragments of tissue that form a small pointed beak (a peristome).

The endoperidium typically lacks any sort of stem (being sessile); it is grayish brown to "wood brown" when young but light yellow-brown in dried, unopened specimens.

The outer tissue layer, the exoperidium, develops splits which radiate from the apex and form between four and eight rays that separate from the endoperidium.

The latter's thin and papery envelope surrounds a mass of spores and fertile tissue known as the gleba. 

Fairly common & are seen all year round in Britain.