The black line is 1 cm. This plant is small!
Aphanes arvensis 29Apr2017 NS9438 PW
Close up of the flowers and the group to the left show the triangular stipule teeth.
Aphanes arvensis 29Apr2017 NS9438 PW
The stipule is clearly triangular and (with the eye of faith!) the constriction below the sepals is arrowed.
Aphanes arvensis NN6258 5July2019 PW
This looks very similar to Aphanes arvensis, very small and easily overlooked.
Aphanes australis NT0332 02 June 2019 PW
The commonest error is to confuse the stipules and sepals.
Aphanes australis NT0332 02 June 2019 PW
This clearly shows the strap-like stipule teeth.
Aphanes australis NT0332 02 June 2019 PW
Aphanes species - Parsley Piert
These two species are very similar, tiny and easy to overlook. They are hairy and leafy - like a tiny sprig of parsley, growing on hard, often stony, ground. The flowers are inconspicuous and the two species can be hard to tell apart.
The problem with Aphanes, apart from its size, is the confusing muddle of green bits.
It has true leaves, which are the largest leaf-like bits. It has clusters of flowers opposite the base of the leaf. Being Rosacea there are stipules at the base of the leaves, surrounding the flowers. These stipules are fused in a frilly curtain. Inside this there is a cluster of 6 or more, petal-less flowers which are formed from 4 green sepals,
The identification depends on the stipules and the sepals.
Aphanes arvensis, Parsley Piert. The lobes of the stipules are equilateral triangles, about as long as they are broad. The sepals tend to be erect or open slightly out. So when looking down on top the flowers look open and from the side they appear tubular and then broaden out. The fruits are 2 - 2.5mm.
Aphanes australis, Slender Parsley Piert, has strap-like stipules, noticeably longer than wide. The sepals are erect and slightly incurved. So when looking down on top, the flowers look closed and from the side they appear tubular and narrowing to a point. The fruits are 1..4 - 1.8mm. Overall it is an (even) smaller plant.