Synonyms: Crataegus apiifolia, C. curvisepala, C. dissecta, C. oxyancanthana, C. oxyacantha var. monogyna, C. oxyacantha v. paulii, Mespilus monogyna, Oxyacantha apiifolia, others.
Common names: English hawthorn; common hawthorn; oneseed hawthorn; May tree; singleseed hawthorn; azzarola; neapolitan medlar; oneseed hawthorn; whitethorn;
Crataegus monogyna (English hawthorn) is a deciduous shrub or small tree (family Rosaceae) found in California along the north and central coast and in the North Coast Ranges. English hawthorn was introduced to California as a landscape ornamental. It has escaped cultivation, growing in moist soil in riparian areas, woodlands and grasslands. At about 10 years of age, the trees begin to produce bright red fruits that are consumed by birds and other animals, who distribute its seeds. The seeds may also be dispersed by human activity or soil and water movement. Effective control may be achieved by manually removing seedlings, cutting down the trees and either removing their roots or painting the trunk with herbicide.
High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.
A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
* – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
-* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.
Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
Weed Management Notes
Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.
Cal-IPC Newsletter Articles
There are no newsletter articles associated with this species yet.
Cal-IPC Symposium Presentations
Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.
There are no Symposium presentations associated with this species yet.
Other Crataegus monogyna Information
CalPhotos - Images of plants taken mostly in California.
Calflora - Distribution map and records of this species in California.
CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
EDDMapS - Distribution of this species in North America.
Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.
Additional photos
Crataegus monogyna (English hawthorn) flowers. Photo: JM DiTomaso
