Flower:

1 to a few clusters of up to 6 flowers each, at the end of branching stems. Flowers are white, 1/16 to 1/8 inch across, have 4 petals with pointed, blunt or rounded tips, 4 black-tipped stamens, and short stalks.

Leaves and stem:

Leaves are whorled in groups of 4, 5 or 6, mostly 4 along the stems and mostly 5 where stems branch. Leaves are 1/3 to 1 inch long, to ¼ inch wide, with blunt tips, and are sometimes widest at the tip end. There are tiny hairs along the leaf edge and sometimes the midrib on the underside; the texture is smooth. Leaves in a whorl are not always consistently sized, and are often unevenly spaced. Stems are angled and smooth, though there are typically short hairs at the leaf nodes. The plant tends to grow sprawling, often forming mats.

Fruit:

Fruit is typically a pair of tiny, smooth round pods, each containing a seed, though sometimes only one side develops seed.

Notes:

Bedstraws can be difficult to distinguish. The leaves of Bluntleaf Bedstraw most closely resemble those of Stiff Marsh Bedstraw (Galium tinctorium) but the latter has 3-petaled flowers and rough textured leaves and stems, where the former has 4-petaled flowers and smooth leaves and stems. Also similar is Labrador Bedstraw (Galium labradoricum), which also has smooth leaves, stems and fruit but has leaves all whorled in 4s, and flowers clustered more consistently in 3s. There are 3 varieties (or subspecies, depending on the reference) of G. obtusum, with var. obtusum found in Minnesota, and central and eastern North America. The other 2 are limited to the southeast US.