A Wandering Botanist: Western Nebraskan Plants Easily Seen At Cedar Point Biological Station

Recently at the University of Nebraska's Biological Station, Cedar Point, at the Station's 50th anniversary, I failed to take very many photos of buildings and people. Here are a few of the photos of plants I took, instead.

buffalo burr, Solanum rostratum

For example, buffalo burr (Solanum rostratum, tomato family Solanaceae). Native to North America, it gets its name from its presence in areas denuded of other plants by bison, and since then, by cattle.This big-flowered plant has impressive spines (look next to uppermost flower in the photo above). The burs will stick to animal hair, dispersing it. It is also rich in alkaloids that deter insects. It is one of the American plants that has gone around the world as a weed. Okay, it is hated around the world, but it is nevertheless a plant success story. Look and don't touch.

I walked the paths close to the buildings and found numerous interesting native wildflowers and a few common weeds. Every plant exceot in this post was listed in Stubbendieck et al., Weeds of the Great Plains, making them weeds. What it means, really, is that these are plants that tolerate trampling and can grow in the severe conditions of bare soil (full sun, rapid evaporation of water, large change in temperature day to night), which characterize areas routinely disturbed by humans, such as close to a busy field station.

This next plant is sandbur, Cenchrus longispinus (grass family, Poaceae). This is a native American plant of trampled areas, especially on sandy soils. The flowers are inconspicuous but develop into seed pods with large spines, the burs. The spines are sharp and barbed, they easily adhere to socks and shoes. Grabbing them to remove them, they stab the fingers. The Flora of Nebraska includes a recommendation: "Moistening the fingers is helpful when attempting to dislodge the burs from stockings and other clothing." (p. 653).

sandbur, Cenchrus longispinus

Below is puncture vine, Tribulus terrestris (caltrop family Zygophyllaceae). This is a weed from Europe. My photo from this year does not show the obnoxious spiny fruits, just attractive yellow flowers; it was too early for the seed pods to be obvious. It is a sprawling prostrate plant, not really a vine, and as an annual, rarely gets big enough to drape over other plants. The flowers are usually open only until midday (this photo about 10:30 am).

puncture vine, Tribulus terrestris,in flower

Here, from a different visit, you can see the fruits. The fruits usually have two or three spines and two to five seeds. The spines are very tough and sharp, bad for grazing animals and barefoot humans. Reseeding every year would seem a tricky proposition but puncture vine has been in Nebraska since at least 1896 and is listed by the USDA as found in nearly every state in the U.S.

puncture vine, Tribulus terrestris, featuring the spiny fruits

The next plant is Russian thistle, Salsola tragus (amaranth family, Amarylidaceae). It is not a thistle though it may be from Russia, originally arriving in South Dakota as a contaminant of flax seeds from Russia. It is an introduced weed with spiny tips on the leaves, so it is unpleasant to bump into. The "thistle" name comes from being spiny, not from a close relationship to thistles like musk thistle (Carduus nutans, sunflower family, Asteraceae). The flowers are green, inconspicuous, and wind-pollinated. When the seeds are ripe, it tumbleweeds, rolling over the ground, dropping seeds. It can be very, very numerous in dry grasslandlands. The genus Salsola has an estimated 130 species, native to Eurasia, of which at least six have become widespread in Noth America. The species are hard to distinguish, especially if no fruits are present.

Russian thistle Salsola tragus

The other plants I'll describe are not prickly. Western Nebraska is a tough place for plants, with light and irregular rainfall, and, now and historically, lots of big grazing animals. Spininess is an important protection from being eaten.

Goldenrod is a big genus of easily 100 species with some 70 in the United States. This is stiff goldenrod, Solidago rigida (sunflower family, Asteraceae). Goldenrods are called weeds because they are common plants of pastures and roadsides and neither grown as crops nor favored as forage for livestock. In fact, they are handsome native wildflowers which attract and feed a lot of pollinators, bees, butterflies, flies, beetles, and others.

stiff goldenrod, Solidago rigida

Wild four o'clocks are in the genus Mirabilis (four o'clock family, Nyctaginaceae). The garden four o'clock is Mirabilis jalapa, from Peru. Nebraska has six native species, North America has 21. This is the hairy four o'clock, Mirabilis hirsuta, the most widespread and common. Four o'clocks have pretty red purple, occasionally white, flowers that open in the afternoon (four o'clock) and stay open until dark, so it is easy to miss the flowers. The bracts around the flowers are green, turning yellow and star-shaped, so are often mistaken for flowers. Inside the bract are the seeds. (The thing that looks like a butterfly in the photo below is a piece of paper on the ground.)

four o'clock Mirabilis species

Western toothed spurge, Euphorbia dividii, is my next plant. The genus Euphorbia is huge, with over 2,000 species. North America has 139 species. Some, like leafy spurge, Euphorbia escula, are introduced from Eurasia and have become serious problems for crops and in pastures. Others, like toothed spurge, below, are common, often found in disturbed areas, but rarely cause problems. Toothed spurge is native, and never very tall. You can see from the spots and the shape, that it is related to poinsettias, also in the genus Euphorbia. (Poinsettia is Euphorbia pulcherrima, a big woody Euphorbia from Mexico. ) "Toothed" refers to the jagged edges of the leaves, one of the ways to identify western toothed spurget. Recent study has divided toothed spurges into eastern and western species. The eastern species kept the name Euphorbia dentata, the western one, which this is, got a new name, Euphorbia davidii. The seeds develop inside round fruits in the center of the plant and when ripe, split violently apart, throwing the seeds, usually three, in different directions.

western toothed spurge, Euphorbia davidii

Skeletonweed, Lygodesmia juncea, sunflower family, Asteraceae, has these pretty white and purple flowers. A native perennial, it rarely gets a foot tall. I think the weed book lists it because under some conditions it becomes common in rangelands and it is bitter and generally unpalatable to livestock. The name skeletonweed is because the leaves are very thin and inconspicuous; it seems to be all stems, the skeleton of a plant.

skeletonweed, Lygodesmia juncea

Broomsnakeweed, Gutierezia sarothrae (sunflower family, Asteraceae) reaches its eastern limit in Nebraska; it is found all over the western U.S. A rounded plant that produces many yellow flowers in late summer, it is considered a weed because it can become quite abundant and is very poor forage for livestock. Generally, it is only common where pastures are badly managed. The broom in its common name is because the nice round shape and strong branches made it a good improvised broom for both Natives and settlers. It is called snakeweed because it was used in treating snakebite.

broomsnakeweed, Gutierrezia sarothrae

Redwhisker clammyweed, Polanisia dodecandra (cleome family, Cleomeaceae) is one of a genus of just five species, all native to the United States and Mexico. This is the most widespread species of the five but not much of a weed, though it does like open sandy spots. It is in Stubbendieck's weed book because the flowers can be reddish and then it looks a lot like Rocky Mountain bee plant, Cleome serrulata, which is a common weedy annual.

Redwhisker clammyweed, Polanisia dodecandra

Finally, this one is NOT in the Weeds of the Great Plains, sand bluestem, Andropogon hallii (grass family, Poaceae), seen as the tall yellowish grasses topped by seed stalks in groups of three. Sand bluestem is a variant (derived species or subspecies) of big bluestem (Andropogon gerardi) found mainly in the Nebraska Sand Hills and sandy spots in surrounding states. It is a sand-adapted plant, with thick waxes to retain water, making it appear yellowish or even blue (big bluestem is usually distinctly reddish) and with strong rhizomes for rising up or digging down if the sand it is growing on shifts (a common thing. It forms sprawling clones rather than the tight clumps of big bluestem. Like big bluestem, sand bluestem is excellent forage for cattle, especially in early summer. (Sand bluestem and big bluestem hybridize; I didn't check these and Cedar Point, where several ecosystems meet, is a good place to look for hybrids.)

sand bluestem, Andropogon hallii

I did not do much filtering of the plants I photographed around the Station for this post, so this is a good sample of what I saw. Weedy plants are the ones that survive in areas with high levels of human activity. Spiny plants teach people to walk around themselves, reducing the damage they take. Clinging spiny fruits carry the seeds to new open areas. All of these plants, sand bluestem included, grow well on open sandy spots, so the edges of Cedar Point Biological Station's paths and unpaved roads are good habitat for them. Calling a plant a weed can be an insult, but it describes a tough and resilient group of plants, coping well with a human-dominated world.

Comments and corrections welcome.

References

Kaul, R.B., D. M. Sutherland and S. B. Rolfsmeier. 2011. The Flora of Nebraska. University of Nebraska Press. Lincoln NE.

Stubbendieck, J., M. J. Coffin and L.M. Landolt 2003 Weeds of the Great Plains. Nebraska Department of Agriculture. Lincoln, NE. There is a 2005 edition, but that is not the one I used.

A collection of stories about other plants common near Cedar Point Biological Station:

Keeler, K. H. Look Twice. 15 Plants to Notice at Lake McConaughy. Wandering Botanist Press, Loveland CO. Available on Amazon-link, from Cedar Point Biological Station and from me.