The lady's bedsrtaw (Galium verum) is the only member of the bedstraw family which is yellow and, therefore, should be easily recognised. Most bedstraws are white, some are pink or purple and crosswort is green but none are bright golden yellow like this one.
A plant that is common on grassland, especially on lime soils, it is a sprawling, medium sized plant. My book suggests it can grow to a metre tall but I have never seen it that size, usually a foot or so at the most. It flowers from June until September and the yellow spikes are a mass of smaller four petalled flowers. The leaves occur in whorls around the stem at the point the stem branch to form flower heads. The leaves smell of new mown hay and once a upon a time the plant was used to stuff mattresses and the smell of the leaves was supposed to enhance sleep and repel fleas! Naturally, this is how it came by its name. This is another interesting fact from Wikipedia; lady's bedstraw was used as a sedative and considered effective in reducing pain during childbirth and another reason for its name.
Red and yellow dyes can be extracted from this plant and, in Gloucestershire it was used to colour their cheese.