Bull Thistle and Whorled Milkweed in Winter

by Carl Strang

Today’s winter botany focus is on one plant that is very conspicuous and another that is much less so. The conspicuous one is the bull thistle.

The dense, spiny leaves all remain attached, intimidating in winter as in summer.

The dense, spiny leaves all remain attached, intimidating in winter as in summer.

The heads bend to become oriented in various directions.

This is a weed with visual interest, but not what I would call cuddly.

This is a weed with visual interest, but not what I would call cuddly.

Some insects, however, find this plant very approachable when it is blooming.

A tiger swallowtail fills its tank at a bull thistle flower head.

A tiger swallowtail fills its tank at a bull thistle flower head.

For contrast, let’s look at what becomes of whorled milkweed.

Not a very tall plant, whorled milkweed’s narrow leaves further diminish its visual impact even when it is green. Only the flowers grab the eye.

Not a very tall plant, whorled milkweed’s narrow leaves further diminish its visual impact even when it is green. Only the flowers grab the eye.

In winter the leaves fall away.

The foot-tall stems may remain upright or tilted.

The foot-tall stems may remain upright or tilted.

Some of the opened seed pods may remain attached.

The pod’s shape and mottled color pattern on the relatively diminutive stem help with identification.

The pod’s shape and mottled color pattern on the relatively diminutive stem help with identification.

Fortunately this is a plant that tends to grow in colonies, so even if some individuals have lost all their pods and seeds, a few should remain.

Straight-lanced Meadow Katydid

by Carl Strang

The Kankakee Sands bioblitz gave me the opportunity to learn more about the straight-lanced meadow katydid. My only certain identification in northeast Illinois was a male in Kane County last year. I had photographed some females with long ovipositors, but most of these seemed better fits as short-winged meadow katydids. An open area at the Conrad Savanna State Nature Preserve proved to have an abundance of straight-lanced, and they were the only members of their genus (Conocephalus) in that location.

This was a dry sandy-soil spot with grasses, whorled milkweed, hoary vervain, and a Lespedeza species as the major plants.

Mature females left no doubt.

The ovipositor length consistently exceeded the insects’ body length. Some of the literature I had seen had given femur length as the measure, but my experience in northeast Illinois had given me doubts.

Late-instar female nymphs likewise had exaggerated ovipositors.

In this one the ovipositor is much longer than the body.

Though I could hear the incessant buzzing, free of ticks typical of meadow katydid songs, that supposedly marks the straight-lanced song (using the SongFinder, of course), searching and sweep sampling produced just a single male, a nymph in the penultimate instar.

Already the cerci are showing extended flattened tips that will be even longer at maturity. They are long enough here to be diagnostic, I think.

I was paying attention to femur color patterns as well. Note the diffuse blackish stripe on the male nymph. I think this will prove to be diagnostic, when present. It is lacking in the mature female in the first photo, however. From this experience I am inclined to regard body length rather than femur length as the measure the ovipositor needs to exceed on a mature female meadow katydid to be considered a straight-lanced. Going back through my photo records, I found only one that met this criterion.

This one I caught in the dolomite prairie at Waterfall Glen Forest Preserve in 2010. Note the blackish stripe on the femur.

This was one of the two highlights of my singing insect survey at the bioblitz. I’ll share the other in my next post.

Summer Prairie Wildflowers

by Carl Strang

My groundwork for future phenology studies continues at Mayslake Forest Preserve as I record first flowering dates for summer blooming plants, with the greatest number now occurring in prairies and meadows. The first, wild bergamot, has a broad enough ecological range sometimes to grow in open woodlands, too.

Bergamot b

More confined to proper prairies is the yellow (also known as gray) coneflower.

Yellow coneflower b

One of my favorites is the plant from Mars, or so I think of its odd appearance, more commonly known as rattlesnake master.

Rattlesnake master 2b

Butterflies like it, too. Drier prairies are good places to find hoary vervain,

Hoary vervain b

while wetter prairies are home to its congener, blue vervain.

Blue vervain b

Those plants will be much more spectacular looking when they hit their flowering peak, but here I am focused on first blooms of the season. Whorled milkweed, with its linear leaves, has an unconventional look for a milkweed.

Whorled milkweed 1b

Butterfly weed, a milkweed lacking the milky looking sap, arrests the eye.

Butterfly weed 1b

It is protected by internal poisons. Another eye-catcher, the purple prairie clover, is less fortunate. Rabbits love it.

Purple prairie clover b

Towering above nearly all the other prairie species is the compass plant.

Compass plant 2b

Now for some more mints (bergamot was one): the slender mountain mint,

NL mountain mint 2b

the common mountain mint,

Virginia mountain mint b

and germander.

Germander b

The earliest sawtooth sunflower heads always seem to have these odd bits of green popping out of them.

Sawtooth sunflower b

We are late enough in the season that the blazing stars are beginning to bloom. First of these at Mayslake is the marsh blazing star.

Blazing star b

The season’s but half done. There’s much more to come.

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