In spring, the dry stalks of last year's grasses are mixed with the current year's new green growth.
This is what a native grassland should look like--lots of tall grasses with little brush and very few invader species.
Bushy Bluestem, Andropogon glomeratus, has broom-like
inflorescences that
distinguish it from all of the other bluestems.
This is Little Bluestem, Schizachyrium scoparium. It is one of
the most common
grasses in the Blackland Prairie regime.
Splitbeard Bluestem, Andropogon ternarius, is also present.
All the bluestems flower in late summer and fall. Their fluffy
inflorescences make them
easy to recognize.
Before the park was established, this prairie area was used to pasture
cattle. It was
severely overgrazed, with very few native grasses and an abundance of
invader or
increaser species such as Bitterweed, Croton capitatus, and this
Silver-leaf
Nightshade (Solanum elaeagnifolium). Now that the area is
protected, these
weedy species have declined and the native grasses have staged a
comeback.
In addition to grasses, a healthy prairie supports many different herbs.
Legumes are
usually an important part of the flora. False Indigo, Baptisia
bracteata, is
common in local prairies and pastures. The creamy-yellow panicles of
pea-like flowers
poke out from underneath the bushy plants. It's a member of the Fabaceae
or Bean
Family.
Another common legume is Partridge Pea, Chamaecrista fasciculata,
which
blooms in late summer and early fall. It's one of the few local members
of the
Caesalpiniaceae.
The Mimosaceae is represented in the park by several species of
Schrankia and
Mimosa. Look for pink "powderpuffs" beginning in late spring or
early summer.
They have been given the common name of Sensitive Briar because the
leaves fold up
when disturbed.
One can also find Milkweeds in open areas. This is Asclepias
viridis.
The Blackland Prairie and Post Oak Savannah regions of Texas are believed
to be more
densely brushy and woody than they were before the advent of European
settlement.
When wildfires are suppressed, woody plants become more abundant. In
addition,
fencelines which are neither grazed nor mowed provide shelter for woody
species and
often become "corridors" of colonization for trees and shrubs. The line
of trees shown
here follows the path of an old fencerow. It makes a narrow strip of
woodland visible
from the air.
As we continue on through mixed prairie and stands of trees, we encounter
more
wildflowers. Many of them are showy monocots. Yellow Star Grass,
Hypoxis
hirsuta, in the Amaryllidaceae, is a good example.
The Yellow Star Grass looks especially nice with Blue-eyed Grass or
Sisyrinchium. The taxonomy of the local species of
Sisyrinchium is quite
a mess. These plants are members of the Iris family.
Copper Lily, Habranthus texanus. Is another member of the
Amaryllidaceae. It
pops up, seemingly overnight, after soaking rains in the spring and
summer.
Spiderworts (Tradescantia spp.) in blue, purple, and occasionally
pink, are
abundant along the trail.
Unusual features of Spiderwort flowers are the bow-tie shaped anthers and
the furry
filaments. The flowers can be of different colors, depending on soil pH
and other
environmental factors. The cells of the filament hairs mutate easily and
the plants have
been grown near nuclear plants as a biological radiation detector.
