July 07, 2019

Cold tolerance of ligustrum and more on invasives

Seeing the the extreme invasiveness of Ligustrum lucidum (Glossy Privet), I am hoping for a cold winter similar to what we had in Texas 36 years ago, when many were killed. In traveling around to different parks, I see efforts being made to eradicate ligustrum, but it is a difficult one to snuff out and continues to re-seed heavily, so the problem is an ongoing one. In the cold outbreak of 1983-84, temperatures remained below zero for nearly 300 hours for parts of Central Texas and D/FW. In December 1989, we had a cold spell that bottomed out with readings of -4 below on the morning of Dec 23, that totally killed some ligustrum and other to the root. In the 2011 freeze event, we had no real damage to Ligustrum or Oleander, although it did kill a fairly large Washington robusta palm tree we had. I have seen Oleander killed to the ground fairly often, but the pink flowered variety seems to be hardy enough to survive almost any winter that we could be dealt here. I had a red flowered one that was killed in the 1983-4 freeze. Sago palm survived easily the 2011 winter, and I have read of a group of these trees in Northern Mississippi surviving since the 1920's, so they should be safe.
Unfortunately there are many other invasives that cold weather will not harm. But a strong cold spell could help to control ligustrum to some extent, perhaps from Austin north anyway. We need any help we can get on this one.


My top invasive shrubs or trees in Central texas:
1. Glossy Privet (Ligustrum lucidum)

2. Heavenly Bamboo(Nandina domestica)

3. Chinaberry (Melia azedarach)

4. Callery PearPyrus calleryana)

5. Chinese Pistache (Pistacia chineses)

6. Persian Silk Tree(Albizia julibrissin)

7. Tree of Heaven(Ailanthus altissima)

8. Chinese Photinia(Photinia serratifolia)

9. Chinese Tallow Tree (Triadica sebifera)

10. Lilac Chaste Tree(Vitex agnus-castus)

Posted on July 07, 2019 13:48 by lanechaffin lanechaffin | 0 comments | Leave a comment

February 11, 2019

About Live Oaks

This is Quercus fusiformis:

Q. fusiformis in Bexar County., Texas

Quercus fusiformis is the common live oak used in landscaping and found in the wild in central Texas. It is more drought-tolerant and cold-hardy than Q. virginiana, which it is sometimes considered a variety of.
Habitat is one of the best ways to distinguish between the two in the wild.
Quercus fusiformis is typically found growing on dry sites, unlike Q. virginiana, which prefers moister conditions and is found along the coastal areas of the southeastern United States. Q. fusiformis is generally accepted to be the hardiest evergreen oak, able to tolerate winters to USDA zone 6a. It has become a popular landscaping tree for its stately form, ability to endure urban conditions, and general hardiness. It is prevalently used for these purposes in Texas and southern Oklahoma, and use is becoming more widespread into the Western US.

Q. fusiformis can appear as a thicket forming shrub or be a large spreading tree that is identical to Q. virginiana. Q. virginiana is known as Coastal Live Oak, or Southern Live Oak. Q. fusiformis is known as Escarpment Live Oak or Texas Live Oak.


Q. fusiformis in Bell County, Texas

In it's western range, where it is typically scrubbier, Q. fusiformis is easily distinguished from Q. virginiana. But in it's eastern range the differences are less apparent. Interestingly, the state record Q. fusiformis (Ht. 63', circ. 342") is larger than the state record Q. virginiana (Ht. 61', circ. 338"), in height and circumference, but they have the exact same size index of 427 due to the Q. viriniana tree having a greater width.


Note the dotted line along the Balcones Escarpment.

According to Turner's Atlas of the Vascular Plants of Texas, Vol. 1, in Texas Q. virginiana occurs only as far west as eastern Williamson County and eastern Bell County. The majority of the occurrences are east and south of Bell County, mostly clustered along the Gulf Coast. Quercus fusiformis, on the other hand, occurs mainly west of the line of counties including McLennan, Bell, Williamson, Travis, Hays, Comal and Bexar—generally, the Edwards Plateau. There is also a grouping in the southern tip of Texas in the South Texas Plains. Additionally, there is an eastern line of counties (including Goliad, DeWitt, Lavaca, Colorado, Fayette, Bastrop, Washington and Brazos) where Q. fusiformis and Q. virginiana overlap. In its eastern range and especially where the two overlap, is where the confusion abounds. Robert Vines in Trees of Central Texas says about Q. fusiformis:
"Although it appears distinct in the western part of its distribution (beyond the Edwards Plateau area and into Mexico), on its eastern range it seems to pass into Q. virginiana with many intermediary variants."
Benny Simpson says this about Q. fusiformis:
"Escarpment Live Oak grows in mottes, attaining heights of 50 feet (72' has been recorded) on almost any alkaline to slightly acid, well-drained soil. It is rather rare on the the true Blackland Prairies, possibly because of the poor internal drainage of those soils, but it does occur in the West Cross Timbers and Grand Prairie, west and north of the Balcones Escarpment on the Edwards Plateau, and, to a lesser degree, east of the Balcones Fault Line on the Blackland Prairies. It grows in hybrid swarms of Quercus virginiana x Q. fusiformis from the Balcones Escarptment to the coastal area and then eastward to the Brazos River, where, on the east side, more or less pure forms of Q. virginiana are encountered."

From Flora of North America:
"The difficulty in distinguishing Texas populations of Quercus fusiformis from Q . virginiana is reflected in a variety of taxonomic treatments, including reducing Q . fusiformis to varietal rank under Q . virginiana . The latter disposition is problematic, however, because Q . fusiformis in northeastern Mexico is amply distinct from Q . virginiana and appears to be more closely related to Q . brandegei Goldmann, an endemic of Baja California, Mexico. Thus, here we assume that the intergradation of Q . virginiana and Q . fusiformis is a result of secondary contact, and is not primary clinal variation. Under this interpretation, Q . virginiana in typical form extends into Texas only as far west as the Brazos River drainage along the coast from there to the escarpment of the Edwards Plateau; most populations elsewhere are either intermediate between the two species or show greater affinity with Q . fusiformis . On the Edwards Plateau, the live oak populations are small trees forming rhizomatous copses (shinneries) and having mostly acute acorns."

Q. fusiformis in Young County, Texas

Q. virginiana in Aransas County, Texas

Posted on February 11, 2019 03:17 by lanechaffin lanechaffin | 1 comments | Leave a comment

January 17, 2019

Identifying Ash trees in Texas

White ash (Fraxinus americana) is native to the eastern part of the state. White Ash typically grows 50-80' tall (up to 125') and 40-50' wide. The lateral leaflets with stalks are strongly whitened beneath. Leaflets are often entire or with very shallow teeth. The bud scars are U-shaped. (Important: A leaf scar is the major botanical feature when keying a green or white ash. The white ash will have a U-shaped leaf scar with the bud inside the dip; the green ash will have a D-shaped leaf scar with the bud sitting atop the scar.) White ash 5-9 elongate leaflets, usually 7. The leaves are 8 to 12 inches in length, with individual leaflets 2 to 6 inches in length. White ash is typically a forest tree prefering moist, rich, deep soil and will grow well in a wide range of pH levels. Dark green leaves become yellow and/or deep purple and maroon in fall.

Some botanists believe that Texas ash (sometimes called Mountain Ash) is a smaller drought hardy variety of white ash (Fraxinus americana var. texensis), usually growing from 30-50' tall and 25-35' wide, from which it can be hard to distinguish. Texas ash (Fraxinus texensis) typically has 5-7 leaflets which are more rounded. Olive green to deep green leaves turn brilliant shades of orange, gold, purple or red in autumn. Texas ash is endemic to limestone areas of southern Oklahoma down through North Central Texas and across the Edwards Plateau.

Green Ash (Fraxinus pennsylvanica) typically grows 50-70' tall with an irregular crown up to 45'. sometimes called River Ash often found in riparian zones along rivers and creeks, floodplain forests and even inundated swamps, but it is adaptable to and often found in other growing environments as well. Green ash typically has 7 leaflets and is so named because the color of its leaves is green on both the upper leaflet surfaces and the lower leaflet surfaces. Lateral leaflets gradually narrowed at base into a narrow wing that runs down the upper part of the leaflet stalk. It is extremely variable in twig and leaf pubescence. Leaflets sometimes toothed. Its winter buds are brown and the bud scars flat-topped, half circles. Leaves are medium to dark green and become yellow in fall.

Berlandier or Mexican Ash (Fraxinus berlandier) is found in moist canyons and stream banks in Central Texas to Trans-Pecos Texas; southward into Mexico where it is called Fresno or Plumero. A smaller round-topped tree rarely over 30' tall. Widely planted as an ornamental in west and southwest Texas and Mexico. The leaves are dark green and thickish, 3-5 leaflets, lancelot or obovate, entire or remotely serrate, glabrous above, glabrous below or a few axillary hairs beneath.

Gregg Ash (Fraxinus greggii) Trans-Pecos found on rocky hillsides and arroyo banks. usually shrubby, to 25'. Leaflets usually 3, sometimes 5-7, thick, olive green above paler beneath, winged.

Fragrant Ash (Fraxinus cuspidata) is found in well drained soil in high altitudes in trans-pecos and in Mexico in rocky canyons. Shrubby, small tree to 25', sometimes forming thickets. Leaflets are 5-7, remotely serrate, lancelot or narrowly ovate, dark green, glabrous above paler below. This ash is unique in having floral fragrance and petals.

The Arizona ash tree (Fraxinus velutina) is commonly called the velvet ash and can reach 50' in height, with a 45-60' open crown in ideal conditions. It is an introduced species often sold at nurseries. Native range is in the high mountains and canyons of the Trans-Pecos and along streams, rivers, and dry streambeds. Marketed as being fast growing and drought resistant, but often problem prone and not recommended in most locations. However, the tree will thrive in less than ideal situations such as urban pollution and poor draining soil. Leaflets 5-7, occasionally 3. The upside and underside of the leaf are often tomentose. The leaf margin is serrated. Fraxinus velutina is closely related to Fraxinus pennsylvanica (Green Ash). Foliage turns yellow in autumn.

Fraxinus americana range

Fraxinus texensis range

Fraxinus pennsylvanica range

Fraxinus berlandier range

Fraxinus cuspidata range

Fraxinus velutina range

Posted on January 17, 2019 17:27 by lanechaffin lanechaffin | 1 comments | Leave a comment

Identifying Redbuds

The botanical name for the Eastern, or American redbud is Cercis canadensis, and it is a member of the pea family, Fabaceae. Some taxonomists consider both the Texas redbud (Cercis canadensis var. texensis) and the Mexican redbud (Cercis canadensis var. mexicana) natural localized variations of the American redbud.
In East Texas, in well-drained acidic soil, with regular moisture, the Eastern redbud (Cercis canadensis canadensis) in its typical form is found. It can be identified by its medium sized, dull green leaves, which, like all redbuds, emerge after the blossoms have fallen.

In Central Texas and southern Oklahoma, Texas redbud (Cercis canadensis texensis, formerly C. reniformis) is identified by its medium sized, glossy-green leaves and its ability to tolerate drier, more alkaline soils. more suited to the harsher conditions of Dallas-Fort Worth, Austin and San Antonio landscapes.

The Mexican redbud (Cercis canadensis mexicana) is found in west Texas and northern Mexico, having smaller leaves with wavy margins.

All of these native redbuds have similar flowers in early spring. Typical redbud flowers are, of course, not red. They are normally in the purple-pink range, but also can be rosy pink or white.

Cercis canadensis range map

Posted on January 17, 2019 14:50 by lanechaffin lanechaffin | 0 comments | Leave a comment

January 04, 2019

Id these sometimes difficult trees

*Ailanthus altissima (Tree of Heaven, Chinese Sumac)- Leaves alternate, aromatic, usually odd pinnate, 9-41 leaflets, entire leaf margin except near the base where 1-2 pairs of blunt dentate teeth usually occur, fall color yellow. flowers in spring, fruit samara. polygamo-dioecious. Introduced/non-native/escapes cultivation/invasive. https://www.austintexas.gov/sites/default/files/files/Watershed/invasive/2013_Invasives_guide_small.pdf

*Sapindus saponaria L. var. drummondii (Western Soapberry, Jaboncillo)- Leaves alternate, not aromatic, usually odd pinnate, rachis may be winged. 9-18 leaflets (terminal often absent), entire leaf margin, veins of leaflets off center fall color yellow. flowers in spring. fruit translucent amber drupe. dioecios. Texas native. often suckers and forms groves.

*Pistacia chinensis (Chinese Pistache) - Leaves alternate, slightly aromatic, usually even pinnate, occasionally will have terminal leaflet, esp on sapling trees. 10-16 leaflets, entire leaf margin, fall color orange/red. flowers in spring before leaves, fruit is small red drupe turns blue when ripe. dioecious. Introduced/non-native/escapes cultivation/invasive

*Rhus lanceolata (Prairie Flameleaf Sumac)- Leaves alternate, aromatic, odd pinnate, rachis may be winged. 9-21 leaflets, typically 13-17, entire leaf margin, or with small teeth, fall color red. flowers in late spring early summer, fruit red-brown drupe in tight cluster. diocecios. Texas native.

*Juglans nigra (Eastern Black Walnut)- Leaves alternate, aromatic, odd pinnate 13-23 leaflets, finely serrate leaf margin, fall color yellow. flowers in spring catkins, fruit is round nut. monoecious. Texas native.

Posted on January 04, 2019 21:28 by lanechaffin lanechaffin | 3 comments | Leave a comment