Introduction

Holly osmanthus (Osmanthus heterophyllus), also known as false holly, olive holly, or olive tea holly, is native to East Asia, particularly China and Japan. The plant is cultivated for ornamental purposes in various parts of the world due to its attractive evergreen foliage and fragrant flowers. There are several variegated varieties. Holly osmanthus belongs to the Oleaceae family, also known as the olive family.

Holly osmanthus is ranked 2 on the New York State Invasive Species Tiers, which defines the plant as a highly invasive species with low abundance in most of the state, and a management goal of eradication. The species is ranked 3 in the LIISMA region, which is defined as a highly invasive species with medium abundance and a management goal of containment.

Biology and Habitat

Holly osmanthus is a large, dense, upright, oval-rounded evergreen shrub or small tree that usually grows 8 to 10 feet tall and may grow up to 20 feet tall in the wild.

Holly osmanthus prefers partial shade to full sun in moist, well-drained, acidic soils. It tolerates a wide variety of conditions, including alkaline soils, pollution, drought, heat, and coastal and urban environments. It is resistant to pests, disease, and damage by deer.

The species has been reported in the wild in North Carolina, Virginia, Washington DC, Maryland, Pennsylvania, and New York State on Long Island.

Identification

• • Appearance: Holly osmanthus is an evergreen shrub or small tree with glossy, holly-like leaves that are usually spiny. The deep dark green leaves have entire margins in the upper part of the plant, while those in the lower part tend to have one to seven spiny teeth. The leaves typically have an opposite leaf arrangement on the stems.

• • Flowers: Fragrant, small white flowers appear in clusters, emitting a sweet scent. Flowering typically occurs in late summer to early fall.

• • Fruits: The plant produces dark blue to black, olive-like fruits that contain a single seed.

Similar Species

Holly osmanthus is superficially similar to American holly (Ilex opaca). American holly is a woody, broadleaf evergreen tree that is native to the eastern and south-central United States. Holly osmanthus leaves are arranged opposite while American holly leaves are alternate. The two species often compete for the same habitat. 

Ecological Impacts

• • Invasiveness: When introduced to non-native areas, holly osmanthus can become invasive, displacing native vegetation due to its aggressive growth.

• • Habitat: It is adaptable to a variety of soil types and can thrive in both full sun and partial shade, allowing it to invade a range of ecosystems.

Economic Impacts

• • Negative Impact on Biodiversity: Invasive holly osmanthus can alter ecosystems, potentially reducing biodiversity and disrupting ecological balance.

• • Agricultural Concerns: In some cases, the plant may interfere with agricultural activities or impact crop yields, although this is unconfirmed and needs more research.

Management and Control

• • Manual Removal: Small infestations can be controlled by manually removing the plants, including their roots.

• • Herbicides: Herbicides may be used, but it is important to choose a product that is effective against holly osmanthus and follow proper application guidelines.

• • Prevention: Early detection and prevention are crucial. Avoid planting holly osmanthus. Consider planting American holly or other native holly instead.

• • Native Plant Promotion: Promote the growth of native vegetation to reduce opportunities for holly osmanthus to establish and spread.

Always check with local authorities and conservation agencies for specific guidelines on managing invasive species in your region.

Monitoring & Reporting

LIISMA is currently monitoring and managing holly osmanthus. As reports of the species are collected, LIISMA delineates and manages any early emerging infestations before they become widespread. 

Your reports matter to us – please report the species to iMapinvasives or iNaturalist as soon as you detect it!

iNaturalist is an app and website that can help you record your wildlife observations, identify species, collaborate with others, and access the observational data collected by iNaturalist users. Already using iNaturalist? Join a LIISMA iNaturalist Project to have your invasive species observations automatically uploaded to our projects! Here are some of our projects you can join: Invasive Species in Priority Areas, EDRR Species, LIFERS, Tier 1 Invasive Species, and more!

Want to dive deeper? Check out iMapInvasives to map invasive species like a pro!