Yellow-Wort is a
annual plant of the UK, typically found growing in chalk grassland, sand dunes and waste ground, to a mature height of up to 45cm.
Yellow-Wort is an erect, bluish-green plant with unusual smooth, paired and fused, upturned leaves surrounding the stem. Apart from near the base, these are sited at the nodes, where branching also occurs. Yellow-Wort flowers only open in the sunshine and when closed are protected by long fleshy sepals. They have 7 or 8 petals.
Botanic classification and naming: Yellow-Wort is a member of the Gentian (Gentianaceae) family. The genus name
'Blackstonia' identifies the plant as a Yellow-Wort and its species name 'perfoliata' means 'leaves surrounding stem'.