Invasive Plants of Miller Springs Nature Center

2016

Recently Observed Invasives in the Nature Center

 
Bastard Cabbage – Rapistrum rugosum
Bastard Cabbage - Rapistrum rugosum   Bastard Cabbage is one of the most common herbaceous plants in the North Area. It begins blooming in May and can bloom until November. In the spring massive numbers of tiny yellow flowers dominate the fields next to the pavilion and are very beautiful. It is one of the most difficult invasive plants to eliminate using herbicides as it has developed resistance to many of them. Project Status
 
Chinaberry – Melia azedarach
This is one of the most beautiful of trees in the summer with its deep green leaves and tall trunks. In the winter it can easily be seen because of the hundreds of pale yellow berries hanging like marbles from the branches. Unfortunately its leaves and berries are toxic to animals. The leaf litter also changes the acidity of the soil below the trees making it more basic. This makes it hard for anything but the grasses to grown under these trees. It also has a dead center and this weakens the tree considerably so they often break and fall making themselves a nuisance tree. Project Status  
 
Chinese or Glossy Privet – Ligustrum lucidum
Chinese Privet   This privet is one of the largest privets that one sees in the park and can reach heights of 50 feet. It is found along Bee Suck Hollow by looking for tall trees with narrow single trunks and very large leaves with approximately 7 clear veins. Along with the Japanese Privet these two trees make up 99% of the invasive trees in the nature center. Unfortunately, to control these trees one cannot simply cut them down as they will regrow. One must pull them out by the roots when they are small saplings or treat them with powerful herbicides. Project Status
 
King Ranch Bluestem – Bothriochloa ischaemum songarica
This grass is extremely invasive and has colonized the emergency spillway area and the strip alongside the fence in the parking lot. Unfortunately it will probably be impossible to control by chemical or mechanical means. As can be seen in the parking lot the mature plants form large and low clumps with tall and sparse seed heads showing above.  
 
Giant Reed Grass – Arundo donax
Giant Reed Grass - Arundo donax   This grass is often mistaken for bamboo. It was usually planted along roads and waterways in order to control erosion where it often thrived and became a nuisance driving out all other plants. There are two patches of this tall grass in the park, one of which is being removed by volunteers. One area is near the Iron Bridge and the other on the South River Loop, south segment, west end. Project Status
 
Heavenly Bamboo – Nandina domestica
This bush has beautiful red berries and is occasionally seen in wooded areas throughout the park. The berries can last more than a year as even the birds generally refuse to eat them! It has escaped from local gardens and has spread to many wild areas of Texas. Many of these plants have been removed from the North Loop area, along the Green Pond Access trail and in Bee Suck Hollow. More are still to be found along the creek in Bee Suck Hollow. If one cuts them down or pulls them up they will just regrow from the root fragments and so are difficult to control. Project Status   Heavenly Bamboo - Nandina domestica
 
Japanese Honeysuckle – Lonicera japonica
  This invasive vine can only be found in a few places in the park. It has beautiful delicate white flower petals and is similar to the native Honeysuckle. To identify the vine look for one large petal on the flower that appears to be 3 or 4 petals stuck together. It is usually an evergreen in this area.
 
Japanese Privet – Ligustrum japonicum
This bushy plant is by far the most invasive plant in the park. It has taken over huge areas along the Green Pond Access trail and in the area where most of the springs are found. If left to itself it will drive out every other type of plant in its vicinity. The result is a serious reduction in native plants, wildlife and insects. The park volunteers are mounting a major effort to remove these in the North Loop and Green Pond Access trail areas but much work remains to be done. Project Status  
 
Malta star-thistle – Centaurea melitensis
Malta Star Thistle - Centaurea melitensis   This plant has one of the more interesting flowers of all of the thistles. It is currently to be found growing along the emergency spillway near the road, on the East bench and on the access road below the dam. Efforts are being made to control it but this will take several years of pulling up the plants when they are found. It blooms in the summertime. Project Status
 
Periwinkle – Vinca major
This plant is extremely invasive and is in the process of taking over large areas in the SE part of the park. It is also found just above Bluff Falls. It has beautiful flowers in the fall. Unfortunately, as can be seen here, it completely crowds all of the undergrowth in the areas where it grows. As a result the variety of insects and wildlife that can be supported is severely diminished.   Periwinkle - Vinca major

 

Other Invasives seen in the park

Common Name Latin Name Occurrance Locations Status
Common Mullein Verbascum thapsus 95% Eliminated Stone Bridge, west side Details
Johnson Grass Sorghum halepense Occasional North Parking Lot, Mural Wall  
Mimosa Albizia julibrissin 1 tree Prairie Loop, South Segment  
Pampas grass Cortaderia selloana Rare Green Pond edges  
Red-tip Photinia P. glabra × P. serratifolia 1 Tree North Area, North Segment  
Taiwanese photinia Photinia serrarifolia Rare North Area, Bee Suck Hollow  
Salt Cedar Tamarix ramossima Eliminated! Stone Bridge Marsh  
Common Horehound Marrubium vulgare A few dozen plants North Area behind Pavillion, Trail above the Mural Wall