This clearly shows the leaf markings and the red / brown tinge in the middle of the flower.

Trifolium repens NS7947 28May2016 MP

Flower heads are on a long bare stem.

Flowers can be pinkish and Red Clover's flowers can be whitish, but the latter always has leaves close below the flower head.

Trifolium repens NS7143 26Aug2010 MJP

Trifolium pratense 22Jun2017 NS7155 MP

The free part of the stipule is triangular or ovate and abruptly narrowed into a bristle-like point. This differentiates it from Trifolium medium (Zigzag clover).

Trifolium pratense NS6163 02Nov2017 PW

The chevron on leaves is distinctive and differentiates it from T. media which has unmarked leaves.

Trifolium pratense NS6163 02Nov2017 PW

There is an agricultural variant of Red Clover, T. pratense var sativa which is larger and has hollow stems. The chevrons are clear - and the hand gives scale.

Trifolium pratense var. sativum NS 5566 04Sep17 PW

Again, the hand gives the scale of the larger T. pratense var. sativum

Trifolium pratense var. sativum NS 5566 04Sep17 PW

The flower is usually looser with a large amount of white exposed around centre of flower head, unlike in T. pratense. The flower is usually more distant from the first stem leaves.

Trifolium medium NS6764 23Jul2017 PW