(Remember that clicking on any thumbnail image will bring up a larger image.)

We hadn't planned to spend so long exploring--we wanted to get to the Sabinal to swim--but everywhere we looked, there was something else to stop and examine.

The Western Horse-nettle (Solanum dimidiatum--Solanaceae) was quite conspicuous--the flowers can be as much as 5 cm across.  This species has prickly stems and makes a fruit that looks like a small yellow tomato. (Note:  Not edible!)  The foliage is covered with minute, star-shaped hairs.  The number of rays on each hair (usually 8 or more)  tells you that this is Solanum dimidiatum and not S. carolinense, which has stars with fewer rays.

Minute details also serve to separate species of Venus' Looking-glass (Triodanis--Campanulaceae.)  Species identification involves the presence or absence of hairs on the leaves, the shape of the floral bracts (ovate vs. long and narrow), the position of the pore or opening in the capsule (at the top, near the bottom, or in the middle), the direction of pore opening (bottom to top or vice versa), and the surface texture of the seeds.  Given that the plant in the images below appears to have ovate floral bracts, pores somewhere between the base and apex of the capsule, and pores that open from the bottom up, it is probably Triodanis holzingeri.

Bee-balm (Monarda--Lamiaceae) is a little easier to deal with.  Keys ask about the number of floral whorls, the shape of the calyx teeth (easy to see), and the color of the bracts and corollas.  This is Monarda punctata, which has multiple whorls and triangular calyx teeth.  There are several varieties--this specimen has white-marked bracts, and white to pale yellow flowers with purple spots.  The images offer close-up views of the bracts, flowers, lower corolla lip, and stamens and stigma.

The Monarda was unmissable, but we might easily have overlooked the Rough Nama (Nama hispidum--Hydrophyllaceae.) This is a small plant with little purple flowers.  In one form or another, this species grows in vegetation region of Texas except the Pineywoods of deep eastern part of the state.  The plant in the image below has has been nibbled by some critter--usually the petals are smoothly rounded.

Next we found quite a few members of the Asteraceae or Compositae.  The inflorescence in this family is a head or capitulum--a grouping of small florets on a single receptacle. The resulting structure may look like a single flower, but something like a daisy or a sunflower is actually dozens and dozens of tiny florets.

This can be seen in something with large and showy heads, such as this Gaillardia pulchella (Indian Blanket, Firewheel.)  This head is radiate--the flowers in the center are tubular and regularly 5 lobed, while the flowers around the edge have long, flat corollas that are all pulled to one side.  (Each 3-toothed "petal" of the Firewheel represents one flower.)

At maturity, the head will be a cluster of tiny fruits, which in this family are achenes.  Each one is from a separate flower and is topped by the pappus.  In Gaillardia, the pappus is a ring of thin, translucent scales. In other genera, it may be bristles, awns, a crown-like structure, a combination of these, or absent entirely.  The images below are a full head of achenes, a side view of one achene, and one achene as seen from above.

The heads of Hairy Leastdaisy (Chaetopappa bellidifolia) are much smaller (about 3mm across) but are constructed in the same way.  In this species, the central or disk florets are yellow, while the peripheral ray florets are white (and roll under when the plant is picked.)

Machaeranthera pinnatifida (Lacy Tansy Aster) is another composite with radiate heads.  In this case, all the florets are yellow.  Keying to species in the genus requires a good look at the foliage.  The leaves of this species are narrow and pinnatifid (cut into segments.)  Nomenclature in the genus is complex, the species having been variously treated in Haplopappus, Machaeranthera, Diplopappus, Sideranthus, Amellus, Aster, etc., etc.  Take a look at the synonym listings for this species.  What a mess!

Palafoxia rosea (Rose Palafoxia) heads are put together a bit differently.  They are discoid, being made only of disk florets.  In this genus, the styles are often the same color as the corollas and add to the showiness of the head.

Not all of the flowers we found were brightly colored.  We counted at least nine species of grasses (Poaceae) along the road.  Grasses can be difficult to photograph well--in addition to being rather monochromatic, they are often open and airy, making getting just the right focus tricky.  In a habitat shot, they tend to disappear into the background.  Macro-imaging is a different story--under high magnification and with good light, the intricate construction of spikelets and florets is revealed.

This is Ozarkgrass (Limnodea arkansana--subfamily Pooideae, tribe Poeae.)  Note the long awns (bristles) on the lemmas and the anthers peeking out.  Grass flowers aren't showy because they don't need to attract pollinators.  They're stripped down for maximum efficiency in wind pollination--crank out as much pollen as possible and gather it from the air, that's their "strategy."

This is an extreme closeup of the spikelets of  Tumble Lovegrass (Eragrostis sessilispica--subfamily Chloridoideae, tribe Eragrosteae or Cynodonteae.)  The spikelets in this species are sessile--they sit right on the inflorescence branches with no stalk.  At maturity, the entire inflorescence will break off the plant and tumble along the ground, pushed by the wind.  You can see some good line drawings here.

Speaking of traveling, the light is starting to go, and it's time to head for the river.