Crataegus crus-galli (thornless form)Cockspur thorn
科:蔷薇科
Family:Rosaceae
属:山楂属
common name:Cockspur thorn
introduce:Plant Type: Tree
Family: Rosaceae
Missouri Native: Yes
Native Range: Quebec to north Caroliina and Kansas
Height: 20 to 30 feet
Spread: 20 to 35 feet
Bloom Time: May
Bloom Color: White
Sun: Full sun (only)
Water: Medium moisture
Maintenance: Medium
General Culture:
Grow in average, medium moisture, well-drained soils in full sun. Tolerates a wide range of soils as long as drainage is good. Tolerates light shade and some drought. Tolerates many urban pollutants.
Noteworthy Characteristics:
Cockspur thorn species plants (see C101 in this PlantFinder) are native from Quebec to North Carolina and Kansas. The numerous sharp thorns of species plants make them inappropriate for placement in many areas with small children or pedestrian traffic. Thornless forms of this plant are now available in commerce and should be considered as userfriendly alternatives. The thornless plants also typically grow as a dense, low-branched, broad-rounded trees to 20-30?with horizontal branching or as tall, flat-topped shrubs. Obovate to oblong-obovate dark green leaves (to 3?long) have wedge-shaped bases. Foliage turns orange to scarlet to purple red in fall. White flowers (in corymbs to 3? bloom in May for a period of 7-10 days. Flowers emit an unpleasant fragrance. Flowers are followed by rounded fruits (3/8?diameter) that ripen in September-October and typically persist to late fall. Fruits are technically edible, but are usually best left for the birds. The fruit is sometimes called a haw. The white hawthorn blossom (Crataegus) is the Missouri State Flower.
Problems:
Pests and diseases are a problem with most hawthorns. Plants are susceptible to cedar hawthorn rust (rust stage where eastern red cedars are present in the area) and fireblight. Other potential diseases include fungal leaf spots, powdery mildew, cankers, apple scab, leaf blight and twig blight. Potential insect pests include aphids, borers, caterpillars, lacebugs, leafminers and scale. Red spider mites may also occur. Use of pesticide sprays may be advisable in areas where this plant suffers from significant diseases and insects.
Uses:
Small flowering landscape tree for lawns or open woodland areas. Lack of thorns expands planting options. Notwithstanding disease susceptibility, a well-maintained tree can be ornamentally attractive.
