Acer palmatum Japanese maple Aceraceae ACPA*; Bx, cf, wv; K (DeCandido 2001); R, gb, r;

Acer palmatum.Jeff McMillian @ USDA-NRCS PLANTS Database.IL.jpg.jpg

Acer palmatum. ©Jeff McMillian @ USDA-NRCS PLANTS Database (Accessed 5/2014).

Acer palmatum is a small tree to about 6 m tall, often multi-stemmed, bark smooth, gray; twigs green-red. 

Leaves opposite, to 10 cm long, about as wide, green to red, deeply palmate 5-9 lobed and toothed, lobes long, narrow, tips pointed, smaller than leaves of other maple. 

Flowers red-purple, radially symmetrical, small, in umbrella-shaped clusters; blooms May-June. 

Acer palmatum fruit. tree-guide.com

Acer palmatum fruit. tree-guide.com (Accessed 5/2017).

Fruit dry thin, flat, winged seeds (samaras), joined end-to end, arched pairs of winged samaras to 2 cm long, wings incurved, Sept.-Oct. (Dirr 1990). 

Wetland status: UPL. 

Frequency in New York City: Very infrequent in natural areas. 

Origin: Korea, Japan. 

Habitat: Escaped from cultivation into woods. Shade tolerant. 

Notes: Infected by Botrytis cinerea (Deuteromycotina), and anthracnose appearing as dark, necrotic, spots or scorch-like appearance, caused by Kabatiella apocrypta, Ascomycotina (Dirr 1990; Sinclair et al. 1987; Agrios 1988).