Plant Natives!

Non-native, invasive, Nandina - Please avoid planting this and consider removing it from

your landscape.  It is a pest in our parks and preserves.

Spring is the ideal time to think about planting, and how you manage your garden or landscape can have an effect on the overall health of the soil, air, water and habitat for native wildlife as well as our human community. Help conserve and improve the quality of these resources by using sustainable gardening practices such as mulching and composting, reducing or eliminating lawn areas, xeriscaping (planting native, drought-tolerant plants), installing rain barrels, and removing non-native invasive plants and restoring native ones.

The U.S. government defines an invasive plant species as one “that is not native to the ecosystem under consideration and whose introduction is likely to cause economic or environmental harm or harm to human health.” These species grow outside desired boundaries, out-competing native species, and spread by seeds, berries, spores, runners, rhizomes, and stems. Some can be easily transported long distances, and every year millions of our tax dollars and thousands of volunteer hours are spent trying to eradicate them.

Many of these plants have already invaded our preserves and greenbelts in Austin, originating in our landscapes, escaping cultivation and spreading into the wild. Invasive species may grow faster, taller, or wider and shade out native species. Many stay green later into the season or leaf out earlier, giving them an advantage over natives. They can change the vertical and horizontal structure of ecosystems, alter hydrology, and disrupt nutrient cycles, all of which can have devastating effects on native plants and animals.

Although invasive exotics may offer birds fruit, squirrels nuts, and hummingbirds and butterflies nectar, they do not provide the entire range of seasonal habitat benefits that an appropriate locally native species will provide. If we want not only to satisfy our desires to attract wildlife, but also to restore the critical, often unseen, small pieces in our ecosystems, we need to bring back our locally native plants. These plants are not only attractive to humans, they also meet the food and cover needs of all wildlife species: bees, wasps, butterflies, grasshoppers, bugs, beetles, spiders, and thousands of others that sustain and support food webs which songbirds, salamanders, bats, toads, and box turtles more visibly demonstrate.

Escarpment Black Cherry is a beautiful native tree that makes a great replacement for the

highly invasive privets or ligustrums.

Aside from attracting a diversity of wildlife, the use of native plants minimizes the impact our landscapes have on the natural environment around us. They reduce water consumption, eliminate the need for chemical fertilizers and pesticides, and limit the competition from invasive exotics. This results in a much healthier habitat—water, soil, and air—for humans and animals alike, and is less costly, too. Invite wildlife to put on a show in your backyard by replacing the invasives in your landscape, and encourage your neighbors to do the same.

Non-Native/Invasive Plant(s)	Some Native & Adapted Alternative(s)
Bamboo	Wax Myrtle (Morella cerifera) Yaupon Holly (Ilex vomitoria) Bamboo Muhly (Muhlenbergia dumosa)
Chinaberry	Chinquapin Oak (Quercus muehlenbergii) Texas Red Oak (Quercus buckleyi)
Chinese Tallow Tree	Bigtooth Maple (Acer grandidentatum) Lacey Oak (Quercus laceyi)
Elephant Ear	Arrowhead (Sagittaria latifolia ) Crinum Lily (Crinum americanum) Pigeonberry (Rivina humilis) Frogfuit (Phyla nodiflora) Horseherb (Calyptocarpus vialis)
Giant Cane	Roughleaf Dogwood (Cornus drummondii) Yaupon Holly (Ilex vomitoria)
Japanese Honeysuckle	Coral Honeysuckle (Lonicera sempervirens) Passion Vine (Passiflora foetida or incarnate or lutea or tenuiloba) Rock Rose (Pavonia lasiopetala)
Holly Fern	River Fern (Thelypteris kunthii)
Kudzu, English Ivy, Vinca	Virginia Creeper (Parthenocissus quinquefolia) Trumpet Vine (Campsis radicans) Coral Vine (Antigonon leptopus)
Ligustrum (all species) or Common Privet	Evergreen Sumac (Rhus virens) Barbados Cherry (Malpighia glabra) Yaupon Holly (Ilex vomitoria) Possumhaw Holly (Ilex decidua) Texas Sage (Leucophyllum frutescens) Cherry Laurel (Prunus caroliniana) Black Cherry (Prunus serotina)
Mimosa	Desert Willow (Chilopsis linearis) Texas Redbud (Cercis canadensis var. texensis  ) Elbowbush (Forestiera pubescens )
Nandina or Heavenly Bamboo	Texas Lantana (Lantana urticoides) Bush Germander (Teucrium fruticans) Texas Sage (Leucophyllum frutescens)
Paper or White Mulberry	Red Mulberry (Morus rubra) Texas Persimmon (Diospyros texana) Possumhaw Holly (Ilex decidua) Cherry Laurel (Prunus caroliniana)
Pyracantha	Yaupon Holly (Ilex vomitoria) Possumhaw Holly (Ilex decidua) Evergreen Sumac (Rhus virens)
Red-tipped or Chinese Photinia	Evergreen Sumac (Rhus virens) Carolina Buckthorn (Frangula caroliniana) Yaupon Holly (Ilex vomitoria)
Russian Olive	Texas Persimmon (Diospyros texana)
St. Augustine Grass	Buffalo Grass (Bouteloua dactyloides)
Tamarisk or Salt Cedar	Bald Cypress (Taxodium distichum) Arizona Cypress (Cupressus arizonica)
Tree of Heaven	Chinquapin Oak (Quercus muehlenbergii) Lacey Oak (Quercus laceyi)
Vitex or Chastetree	Texas Pistachio (Pistacia mexicana) Mexican Buckeye (Ungnadia speciosa)
Wisteria	Passion Vine (Passiflora foetida or incarnata or lutea or tenuiloba) Trumpet Vine (Campsis radicans)

Whorled Wonders

Great Plains Ladies Tresses

The spiral, which is a fundamental form in nature, is most splendidly illustrated in a genus of wild, native orchids called Spiranthes.  Commonly known as ladies tresses, the genus name comes from the Greek speira meaning ‘coil’ and anthos meaning ‘flower’, and refers to each species spirally arranged inflorescence.  The most predominant species of orchid found in Texas prairies, several members of this genus are colonizers of sparsely vegetated areas, appearing on newly disturbed sites such as roadsides and cleared fields, increasing in number until outcompeted by other vegetation.

Of the 15 native Spiranthes species in Texas, several are so similar in appearance that either a hand lens or microscope is often needed to distinguish one from another. To add to the confusion, many closely related species are also known to hybridize. However, Central Texas, the most common include the Great Plains Ladies Tresses (S. magnicamporum) and the Nodding Ladies Tresses (S. cernua).  

Great Plains Ladies Tresses has 2 to 4 narrow, grass-like basal leaves, up to 6 inches long, that are usually absent or withering during the flowering period.  The flower spike can range from 4 to 24 inches tall, and is made up of 12 to 54 small white tubular fragrant flowers, tightly or loosely spiraled, that nod abruptly from the base.  Blooming from September to November, it prefers calcareous grassland habitat, often growing in association with our native Seep Muhly.  In wet years, this orchid may appear in robust spikes numbering in the hundreds, and in dry years it may not flower at all.

Nodding Ladies Tresses has 3 to 5 narrow, grass-like, basal leaves, 8 to 10 inches long, and are typically present at flowering.  It has a flower spike that can grow from 4 to 19 inches tall, and consists of 10 to 50 small white tubular flowers, tightly or loosely whorled in 2 to 4 rows along the upper portion of the stem.  Blooming from late September through November (and sometimes even into December), it can grow on wet or dry sites, but prefers more acidic, sandy soils.

Flowers of Spiranthes orchids begin opening at the bottom of the inflorescence.

Like most orchids, the flowers of these Spiranthes species are resupinate, or twisting during development into an upside-down position.  In fact, the tendency of the flowers to droop slightly gives the Nodding Ladies Tresses both its common and species name, for cernua comes from the Latin and means ‘drooping.’  Unlike other closely related species, the flowers of the Nodding Ladies Tresses have little or no fragrance, but like other closely related species, the flowers are pollinated by bumblebees.  As with most Spiranthes, bumblebees start at the bottom and move upward on the inflorescence in search of nectar. Older flowers at the base of the flower stalk have more nectar, which makes them an efficient first stop for the foraging bumblebees.

As mentioned above, many Spiranthes are difficult to identify to species, and both the Great Plains Ladies Tresses and the Nodding Ladies Tresses are no exceptions.  In fact, Nodding Ladies Tresses is known as a compilospecies, which is defined as a genetically aggressive species that incorporates the heredities of a closely related species by hybridization through unidirectional gene flow, and may even completely subsume that species over time.  Now that’s a whorled wonder!

Silent Flight

Eastern Screech-Owl

Owls have fascinated man from time immemorial – to some cultures they are symbols of wisdom, while to others they are harbingers of doom and death.  Adding to the mystique of these creatures is that they are mainly active at night, using their exceptional vision, acute hearing, and silent flight to stealthily hunt down their prey.

Common in Central Texas, the Eastern Screech-Owl is found in wooded suburban and rural areas and readily nests in tree cavities as well as man-made nest boxes.  A small owl 6-10” long with a wingspan of 19-24”, it has feathered ear tufts and is normally gray, brownish-gray, or less commonly reddish-brown.  The Eastern Screech-Owl eats a variety of small animals, and each night consumes from one-quarter to one-third of its own body weight.  It uses a soft trilling call to keep in contact with a mate or family members, and the male’s trill can advertise a nest site when courting a female or signal an arrival at the nest with food.  This owl also has a descending whinny, which is used to defend its territory.  Eastern Screech-Owl pairs are usually monogamous and remain together for life, although they will take a new mate when one dies.  In mid-April, the female lays 3-4 eggs on average, and the downy white owlets emerge from the nest by mid-May.

Great Horned Owl

Also common but much larger at 18-25” long with a wingspan of 40-57”, the Great Horned Owl prefers habitats of secondary-growth woodlands mixed with open meadows.  Often found perching next to an open area and nests in tree hollows, broken off snags, or nests made by other large birds.  It has prominent ear tufts spaced widely on its head, a brownish-gray body with dark barring, and a rusty facial disk edged in black surrounding each of its orange-yellow eyes. The Great Horned Owl has a broad diet of small mammals, birds, amphibians, and reptiles, and is the only animal the regularly eats skunks.  They have a large repertoire of sounds, but the most common is that of the male’s resonant territorial call ‘hoo-hoo hoooooo hoo-hoo’ that can be heard over several miles through the canyons on a still night. These owls are solitary in nature, only staying with their mate during the nesting season of January and February. Typically 2-4 eggs are laid and incubated solely by the female, until the young start roaming from the nest six to seven weeks later.  

The structure of an owl’s feather is the main reason they can fly so silently.  The leading edge of their primary wing feathers are serrated like a comb, which breaks down the turbulence into smaller, micro-turbulences.  The soft, tattered edges of their secondary feathers allow those small currents of air to pass through them and further reduce the turbulence behind their wings.  In addition, the velvety down feathers found in the wing linings and on their legs further dampen and absorb sound frequencies.  Together, these features allow the owl to greatly reduce the overall noise caused by the turbulence of air flowing over them as they fly.  

The Preserves Around Us

Golden-cheeked Warbler, Setophaga chrysoparia

One of the main reasons Austin is such a wonderful place to live is because it is interlaced with a patchwork of preserves, which together comprise the Balcones Canyonlands Preserve (BCP) System.  In 1992, voters in the City of Austin passed Proposition 10, approving $22M in bonds for the sole purpose of acquiring and improving lands to protect air and water quality, conserve endangered species, and provide open space for passive public use. Jointly owned and managed by the City of Austin, Travis County, the Lower Colorado River Authority, the Nature Conservancy, the Travis Audubon Society, and private landowners, the BCP’s ultimate goal is to set aside 30,428 acres that contribute to the quality of all life here in Austin. 

A multi-agency conservation effort that operates under a regional permit issued under the Endangered Species Act by the U.S. Fish & Wildlife Service, the BCP consists of several tracts of land in western Travis County.  It is important to note that a ‘preserve’ is different than a ‘park’, and is set aside for the purpose of maintaining a natural state rather than developed for recreational use.  The BCP protects prime habitat for the endangered Golden-cheeked Warbler, a bird species that is found only to breed within Central Texas’ specialized mix of native, mature Ashe Juniper (often incorrectly called ‘cedar’) and stands of Live, Spanish, and Shin oak trees.  This type of mixed oak-juniper woodland grows mainly on our moist steep-sided canyons and slopes, providing the warbler with the food, water, and nest-building material it needs to breed.  

Black-capped Vireo, Vireo atricapilla

In addition to the Golden-cheeked Warbler, 7 other endangered species make the preserve system their home, including the Black-capped Vireo, Tooth Cave Ground Beetle, Tooth Cave Pseudoscorpion, Tooth Cave Spider, Kretschmarr Cave Mold Beetle, Bone Cave Harvestman, and Bee Creek Cave Harvestman.  These last 6 species are called karst invertebrates, arthropods that spend their entire existence underground in karst formations.  These karst features, such as caves, sinkholes, cracks, and crevices, were formed by the dissolution of calcium carbonate in limestone bedrock by mildly acidic groundwater.  Over 70 other rare plant and animal species also exist on the preserves, making this region one of the most biologically diverse areas in the country. As such, Central Texas is happily home to more habitat conservation plans than any other region in the United States.   

These wild and beautiful areas require management plans in order for them to remain pristine habitats.  This includes establishment of secure boundaries and rules for access control, maintenance of appropriate trails, species monitoring, habitat enhancement, and – last but not least – public education and outreach to promote good neighbor relations.  As Austin residents, we can do our part to become stewards of these unique habitats.  While in the preserve system, we can stay on marked trails, travel only on foot, and “take only photographs, leave only footprints.”  In our neighborhoods, especially those that border preserve tracts, we can landscape with native plants, remove invasive plants, eliminate pesticide use, be responsible pet owners, practice water conservation, and always respect preserve boundaries.

Most importantly, we can all minimize further negative impacts on the fragile habitat that surrounds our neighborhoods by caring for the preserves through volunteering.  Some of the activities you can become involved with in the preserve system include long-term habitat restoration, gathering and planting native seeds, removing non-native invasive plants, leading guided hikes, and learning about and sharing your knowledge of the native plants and animals that make this such a special place to live.  For more information, visit the Balcones Canyonlands Preserve website at http://www.austintexas.gov/bcp.