Large stipules surround the stems (stipules are small leaf-like structures). These distinguish it from Yellow Avens (Geum aleppicum).
Similar species: Catlings Avens (Geum X catlingii) - Paler yellow and sparser flowers. White Avens (Geum canadense) - White flowers. Yellow Avens (Geum aleppicum) - Stipules do not surround the stem. Also the stems are stouter. Water Avens (Geum rivale) - Flowers are very different.
This is a very invasive non-native plant. Pull it up if you find it in your garden, or else it will spread quickly. The large stipules distinguish this species from Yellow Avens (Geum aleppicum).
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