Notes on Crataegus monogyna

Crataegus monogyna Jacq. (Rosaceae) (Finland, Lohja, Paloniemi, 2003). – Image: Harri Harmaja (scanned from fresh leaves, the two upper ones originating from a freshly grown long shoot). – A solitary individual was found and collected by me on October 1, 2003. The plant is a 'miniature tree', having one stem and only being about 1.5 m high. This tree has five-lobed leaves, the base of the leaf lamina is about blunt (> 90º), and the stipules (at least in long shoots) are serrate or laciniate. C. monogyna is often slightly different as the leaves have three large lobes, a distinctly cuneate base (< 90º) of the lamina, and almost entire stipules. The locality is a rich wood near the shore of lake Hormajärvi, close to roadside. Obviously, the plant is a naturalized escape from cultivation in some near-by garden. C. monogyna is cultivated as ornamental in Finland, and escaped individuals occur in places. – Previously, one occurrence of that kind was known in Lohja: Pykälä, J. 1992: Lohjan kunnan putkilokasviluettelo. – Julkaisu 4/92. Lohjan kunnan ympäristönsuojelulautakunta. Lohja.