Acer griseum (Franch.) Pax
Acer griseum is a tree.
Acer griseum was already described and the name validly published by Adrien RenÃ© Franchet. It was Ferdinand Albin Pax, however, who reclassified it into todays valid botanical systematics in 1902.
Acer griseum is a species 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 comparatively slow-growing trees have a rounded to broadly spreading canopy and reach heights of 8 to 10 metres. The plants reach a width of 5 to 10 metres.
Wood and Bark
The bark is scaly.
Acer griseum is deciduous. The green, ternate leaves are opposite. The leaflets are ovate and petiolate. They have dentate margins and palmate venation. The surface of the leaves is glabrous. They turn an attractive bright orange to red in autumn.
Flowers and Fruits
Acer griseum produces racemes of pendant, yellow five-stellate flowers in May. The plants are dioecious, pollination takes places by allogamy through animals.
In summer the trees carry schizocarps.
Acer griseum is native to West China.
The trees prefer a sunny situation on dry soil. The substrate should be sandy-loamy or gritty-loamy soil with a pH between 6,5 and 7,5. They tolerate temperatures down to -23Â°C (USDA zone 6).
Classification after Prof. Dr. Sieber
- woodland borders (soil usually rich in humus)
Suited as cemetery plant, avenue tree and as specimen plant.
Maintenance and Propagation
The plants usually need very little maintenance.
Pests and Diseases
Honeydew, galls and distorted leaves are a sign for an infestation with aphids. Use an insecticide or control biologically , e.g. with parasitic wasps or predators such as Aphidoletes aphidimyza.
Root and stem lesions, often in combination with raised rings of bark and pustules nearby, indicate a fungal infection. Generously cut out and destroy affected parts.
Mealy excreta on leaves, flowers or fruits indicate in infestation with caterpillars. Crush eggs, handpick and destroy caterpillars. Also apply insecticide or use biological pest control.
Irregular swelling, so-called 'galls', may be caused by insects, mites, fungi or bacteria. Destroy affected parts. To prevent infection avoid injuring the plants and improve drainage.
Fine webs on the plants indicate an infestation with red spider mites. These sap-sucking insects mainly appear under glass and can be controlled either with insecticide or biologically with parasitic mites.
Sudden wilting and pale green discolouration indicate a fungal infection (phytophthora). Remove infected plants. Avoid by improving drainage and over-fertilization.
- 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.