Acer glabrum var. douglasii
Acer glabrum var. douglasii (Hook.) Wesm.
Acer glabrum var. douglasii, commonly known as Douglas maple, is a tree.
Acer glabrum var. douglasii was already described and the name validly published by William Jackson Hooker. It was Leopold Dippel, however, who reclassified it into todays valid botanical systematics in 1892.
Acer glabrum var. douglasii is a variety in the genus Acer which contains approximately 230 to 296 species and belongs to the family of the Aceraceae (Maple Family). The type species of the genus is Acer pseudoplatanus.
The trees reach heights of 6 to 9 metres, they have a erect habit and produce a single stem. The main growing season is in spring and summer.
Wood and Bark
The bark is smooth and grey.
Acer glabrum var. douglasii is deciduous. The dark-green, simple leaves are opposite. They are biserrate, petiolate and have palmate venation. The surface of the leaves is glabrous. The foliage is porous and turns an attractive yellow, orange to red in autumn.
Flowers and Fruits
Acer glabrum var. douglasii produces corymbs of green five-stellate flowers from May to June. The plants are dioecious.
The trees produce brown schizocarps from summer to autumn.
Acer glabrum var. douglasii is native to Alaska, western Canada, the Northwest of the US and the Rocky Mountains.
The trees prefer a shady situation on moist to wet soil. They prefer sandy-loamy or gritty-loamy soil with a pH between 5,5 and 7,5. The plants need a soil depth of at least 61 centimetres for good growth. They tolerate temperatures down to -29Â°C (USDA zone 5) and need a frost-free period of at least 17 weeks.
Classification after Prof. Dr. Sieber:
- woodland borders (soil usually rich in humus)
Tolerance of special soil conditions
- none: soil salinity, anaerobic soil
- low: drought, calcareous soil
The ornamental value of Acer glabrum var. douglasii lies especially in the attractive autumn aspect.
Maintenance and Propagation
Propagate by sowing. The seeds require vernalization.
Pests and Diseases
- Walter Erhardt, Erich GÃ¶tz, Nils BÃ¶deker, Siegmund Seybold: Der groÃe Zander. Eugen Ulmer KG, Stuttgart 2008, ISBN 978-3-8001-5406-7. (Ger.)
- Christoper Brickell (Editor-in-chief): RHS A-Z Encyclopedia of Garden Plants. Third edition. Dorling Kindersley, London 2003, ISBN 0-7513-3738-2.