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COMMON INVASIVE TREES AND SHRUBS OF CENTRAL TEXAS

1. GLOSSY PRIVET (Ligustrum lucidum) A member of the Olive Family Order Lamiales relative of Fraxinus and Forestiera. L lucidum is monoecious. Abundant berries are mildly toxic to humans but are dispersed by birds over large areas. Sometimes referred to as Tree Privet can grow to 50' tall and live to 100 years old. L lucidum typically remains evergreen in Central Texas but will lose leaves and die back in extreme winters. Native of China, Korea, and Japan. Once popular because it quickly forms a tall evergreen hedgerow. Few positives; may offer limited benefit as cover for wildlife and help to support some insect and bird species. Regarded as a serious ecological threat, L lucidum displaces native plants and alters native habitats. Sometimes confused with Wax-leaf ligustrum (Ligustrum japonicum), but L japonicum has stiffer, wavy leaves, is more compact and rarely escapes cultivation in this area.

2. HEAVENLY BAMBOO (Nandina domestica) Nandina is a clumping upright evergreen shrub in the Barberry Family Order Ranunculales a native of Japan, China, and India. Survives as semi-evergreen to -10 F, zone 6. Grows well in sun or shade. Some specimens are over 100 years old. The plant is monoecious. A popular landscape selection requiring minimal care; rabbit and deer resistant. Some cultivars turning red in winter with many berries; some produce no berries. Seed dispersal by birds (the berries are toxic and birds have reportedly died from eating them), also spreads through roots and forms clumps. Somewhat difficut to remove once established. Provides little benefit in the wild except as cover and is considered an ecological threat which can totally dominate understory habitat.

3. CHINABERRY (Melia azedarach) is a deciduous tree in the Mahogany Family, Order Sapindales, distant relative of Sapindus, Rhus, and Pistacia. Fast-growing, 30-60' tall, hardy to 0 F. It is a valued shade tree in its endemic region of SE Asia, with pleasantly scented flowers, but is usually rather short-lived less than 40 years, and susceptible to wind damage and drought. Sprouts readily from the stump. Potential maximum age of 150 years. Chinaberry trees have allelopathic effects and are resistant to native insects and pathogens, making it a fierce competitor against native trees and almost impossible to eradicate with biological controls. It has become naturalized throughout most of the southern U.S. and is regarded as an ecological threat. All parts of the plant, especially the fruit are poisonous. Chinaberry is monoecious. Seed dispersal by birds. Berries are toxic and birds may show intoxication.

4. CHINESE TALLOW TREE (Triadica sebifera) is deciduous tree growing 24-60' of the Spurge Family, Order Malpighiales, a distant relative of Salix. Native to SE Asia. Generally lives 15-50 years potential maximum age of 100 years. Monoecious. Seeds dispersed by birds and water and may remain viable up to 7 years before germinating. Chinese tallow tree is cold hardy to at least zone 7, where it is known to escape cultivation. Thrives in a wide variety of environmental conditions withstands periods of drought. Chinese tallow doesn't have sun requirements and may be found in full sun to complete shade. Leaves and fruit of Chinese tallow are toxic to humans and cattle. Desirable as an ornamental because it is fast gowing with attractive foliage turning red, purple, yellow-orange or a mix of colors in the fall. Chinese tallow tree is an ecological threat, out-competing and eradicating native species. Arrived in the U.S. in the 1700's as a source of oil for the soap industry.

5. CALLERY PEAR (Pyrus calleryana) Decidous tree of the Rose Family grows 30-50' tall, typically short-lived can live to 150 years. In the Order Rosales, distantly related to Ulmus, Celtis, and Morus. Native of China. Young trees may be thorny. Widely used as a rootstock for pear long before Bradford Pear became a popular ornamental. Desirable for its white flowers and fall foliage which ranges from bright red, to purple, gold, orange and yellow. The rootstock may produce sprouts which can then pollinate the graft and reproduce. Copious amounts of edible fruit are dispersed by birds. Cold hardy to -20 F. Grows best in full sun tolerates shade. Once established Callery pear forms dense thickets that push out native species unable to tolerate deep shade or compete with pear for water, soil and space. A single tree can spread rapidly by seed and vegetative means forming a sizeable patch within several years.

6. CHINESE PISTACHE (Pistacia chinensis) Deciduous tree 30-60' tall. Native to China and Taiwan. Pistache is in the Cashew Family closely related to Rhus and Toxicodendron, in the Order Sapindales. More distantly related to Soapberry, with which it is sometimes confused. Moderate growth rate and usually fairly long-lived, capable of reaching 150 years old. Unlike Soapberry, the roots do not aggressively sucker. Hardy to -10 F. Chinese pistache is a dioecious species and once mature, the female tree will produce large quantities of seeds, dispersed by birds. Chinese pistache has been marketed as a highly desirable landscape tree with beautiful fall foliage of red, neon pink, orange, and yellow. Despite its beauty, it is considered an ecological threat due to displacing native plants and altering wildlife habitat.

7. TREE OF HEAVEN (Ailanthis altissima) Tree of Heaven is a fast growing, deciduous tree to 100' of the Family Quassia, Order Sapindales. Related to Rhus, Sapindus, and Pistacia. Native to China and Taiwan. Cold hardy to zone 4 and has become naturalized in much of the United States. It rarely lives beyond 50 years but can exceed 100 years. Adapted to urban areas and causes damage to sewers and structures; poses a greater threat to agriculture and natural ecosystems. A prolific seeder that establishes dense stands by sending up dozens of root sprouts, pushing out natives. Suckers may emerge 50' from the parent tree. Dioecious. Females heavy seed producers samaras spread primarily by wind, also water. Tree of heaven contains ailanthone, a chemical found to have strong allelopathic effects on the growth of other plants which help it establish and spread. Promoted by USDA in the early 1900's as a fast growing shade tree.

8. PERSIAN SILK TREE (Albizia julibrissin) is a fast-growing, deciduous, short-lived, small to medium sized tree that typically grows in a vase shape 20-40' tall with a spreading, often umbrella-like crown to 50'. Usually lives around 20 years but some specimens may live considerably longer. A member of the Family Fabaceae, silk tree is a relative of Prosopis and Vachellia. Native to Asia. First introduced in the U.S. in 1745. Widely used as an ornamental cold hardy down to about -10 F. Monoecious. Seeds are flattened legumes dispersed by animals or water remaining viable for 5 years or longer. Toxic when consumption is more than 1% of body weight. Because silk tree can grow in a variety of soils, produce large seed crops, and resprout when damaged, it is a strong competitor to native trees and shrubs in open areas or forest edges. Once a popular yard tree because of its fragrant showy pink flowers, it is now considered to be an ecological threat.

9. CHINESE PHOTINIA (Photinia serratifolia) Flowering broadleaf evergreen shrub or small tree in the Rose Family growing to 12-30', rarely taller, and equally wide. Native of China, Taiwan, Japan, the Philippines, Indonesia, and India. Lifespan is 50-100 years. The tree produces high amount of bright, red colored fruits that are small pomes, each containing one to four seeds. The fruits are edible and a food source for various birds which disperse the seeds. Cold hardy to -5 F, zone 6. Being shade tolerant and evergreen, it out-competes native vegetation in wooded areas.

10. LILAC CHASTE TREE (Vitex agnus-castus) Deciduous multi-trunked shrub or small tree 10-20' tall and about as wide. Leaves similar to cannabis. Native to Southern Europe and Western Asia. In the Mint Family Order Lamiales, distant relative of Fraxinus, Ligustrum, and Forestiera. A popular ornamental, drought tolerant and fast-growing with large purple flower spikes that attract an abundance of butterflies and other insects. Monoecious. Escapes cultivation to limestone outcrops and dry creek beds throughout Central Texas; seed dispersal by birds. Hardy to -9 F, but preferring warmer climates. Lilac chaste tree average lifespan is 15-20 years.