Trifolium dubium, the lesser trefoil, suckling clover,little hop clover or lesser hop trefoil, is a flowering plant in the pea and clover family Fabaceae. This species is generally accepted as the primary plant to represent the traditional Irish shamrock. Trifolium dubium is a ANNUAL growing to 0.5 m (1ft 8in). It is not frost tender. It is in flower from May to October, and the seeds ripen from July to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. The plant is self-fertile. It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It prefers moist soil.