Fall Wildflowers

September showers bring October flowers.  That doesn't have quite the ring of the spring version, but around here it's just as true.  Our wildflower season happens any time the rains fall, and this year, following a wet September, we are enjoying a fall wildflower season in central Texas.  On Sunday morning Lee and I drove to the Southeast Metro Park, which is located on north side of Highway 71, about four miles east of the airport, for a walk and some wildflower viewing.

We walked on the primitive hiking trail, a three-mile, foot-traffic-only trail at the back of the park.  The first (0.2 mile) section of the trail was wide and graveled, leading to an overlook of the valley below.  The view of industry, smoke stacks releasing grey clouds into the sky along the recently-constructed tollway, and the foul, rotting smell of the water-treatment plant a few miles up the Colorado River, reminded me of the east- versus west-Austin socio-economic divide.  On the east side of town, on fertile farmland, we have located our dumps, gravel pits, water-treatment plant, and poor, while the image of Austin, of musicians and artists and outdoor enthusiasts, resides in the rocky hill country to the west.

We walked the loop trail (2.1 miles) and, aside from seeing a couple of fishermen at the ponds, we had the trail to ourselves.  The loop trail crossed through a mix of habitats, including open meadows, brushy fields, and woodlands, and passed by two small ponds.  The loop trail was narrow, just a dirt path that had been amended in low-lying areas with bark, but easy to follow as it wound up and down the hillsides.  Along some of the sunny sections, the trail was overgrown by grasses and herbaceous annuals that had grown into the trail during their last rain-inspired growth spurt.  At the highest point on the trail we stepped onto a slab of granite for a view of downtown Austin.  We continued back down to our starting point through shady, cedar (Juniperus ashei) woods, crossing over and through dry stream beds on several hand-made, cedar-post bridges, which were the highlight of the trail.

The plant family that was best represented along the trail was the Asteraceae (also called the Compositae), or the sunflower family.  Broomweed (Amphiachyris dracunculoides or Xanthocephalum dracunculoides) plants grow as massive bouquets of tiny sunflowers.  Each plant produces a single flower stem, which grows up to three feet tall and is highly branched, producing many bright, yellow flowers.  Broomweed plants grow in dry, limestone soils and bloom from July through November.

Broomweed (Amphiachyris dracunculoides)

Frostweed (Verbesina virginica), another sunflower family plant, gets its name from the fact that, after the first hard freeze of the season, the stems of the plant exude water, which freezes along the stems in icicle shapes.  The stems of Frostweed plants have distinctive wings along their length.  Frostweed plants grow at the edges of woodlands and bloom August through November, attracting butterflies with their white flowers.

Frostweed (Verbesina virginica)

Thick patches of Prickly Pear cactus (Optunia macrorhiza), topped with ripe, magenta fruits were common along the trail.  Heavy spider webs hung between the cactus stems and, on closer inspection, supported huge orb-weaving spiders known as Writing Spiders (Argiope spp.) due to the thick XXX pattern that is often found in the center of their webs.

Writing Spider (Argiope sp.) on Prickly Pear Cactus

 
Also common along the trail was Wild Petunia (Ruellia nudiflora), an Acanthaceae-family plant that blooms in showy purple flowers from April through October.  Wild Petunia, a ground cover plant that disperses easily by seed, is a host of butterfly larvae and also provides nectar for butterflies.

Wild Petunia (Ruellia nudiflora)

Snow-on-the-Mountain (Euphorbia marginata), a tall spurge-family plant, was nearing the end of its bloom.  Snow-on-the-Mountain is common in disturbed pastures and along roadsides.  Its showy flowers, bordered by striped leaves all around, are beautiful but the plant is poisonous and definitely should not be touched.  Snow-on-the-Mountain blooms July through October.

Snow-on-the-Mountain (Euphorbia marginata)

Pink, open flowers were all that distinguished Prairie Agalinis (Agalinis heterophylla) from the grasses with which it was growing.  Agalinis is common in grasslands and at the edges of woodlands, where its blooms attract butterflies from June through October.

Prairie Agalinis (Agalinis heterophylla)

The white petals of the Texas Nightshade (Solanum triquetrum) flowers are almost dwarfed by their bright yellow stamens.  Unfortunately, my picture didn't capture the flowers very clearly.

Texas Nightshade (Solanum triquetrum)

The white flowers of the Kidney Wood (Eysenhardtia texana), a large multi-branching shrub of the pea family, were amazingly fragrant.  Even Lee, who had realized that our walk was resembling more of a hike as the sun rose in the sky, slowed down to appreciate the smell of the tiny, white flowers.  Kidney Wood blooms May through October, attracting bees and butterflies.  The large shrubs are also larval hosts of butterflies, and their compound leaves and bean pods provide food for mammals including deer.

Kidney Wood (Eysenhardtia texana)

Wood-Sorrel (Oxalis drummondii), a small pink-flowered herb in the Oxalidaceae family, grew along the trail at the shady edges of the woodlands.  Wood-Sorrel has distinctive, three-part leaves, where each of the three parts looks like a wide, fat "V."  Wood-Sorrel blooms September through November.

Wood-Sorrel (Oxalis drummondii)

Near the end of the loop trail, I saw a familiar plant, Yellow Bitterweed (Helenium amarum), a sweet, small sunflower that also grows wild in my front yard.  Like Broomweed above, but a lot smaller, Yellow Bitterweed also grows as a bouquet of flowers.  Each inflorescence is made of a central, yellow globe surrounded by several, distinctive three-toothed petals.  Yellow Bitterweed grows in grasslands and savannas, or is equally at home in lawns, where it tolerates mowing by blooming low to the ground.  Bitterweed blooms from April through November.

Yellow Bitterweed (Helenium amarum)

Another familiar plant that was growing near the end of the loop trail was Mealy Sage (Salvia farinacea), a plant that is commonly used in landscaping in Austin because it is drought-tolerant and grows well in our dry, limestone soils.  Mealy Sage blooms April through October, providing nectar for hummingbirds, bees, and butterflies.

Mealy Sage (Salvia farinacea)

By the end of the loop trail, the midday sun was overhead and we were hot and itchy from wading through flowering grasses, hopping over fire ant mounds, and clearing the trail of spider webs, worrying with each web that maybe we had awakened another huge spider.  Back on the wide, graveled main trail, I hurried to catch up with Lee, who had disappeared over the hill ahead, racing for the car.