Tuesday, August 14, 2012

Partridge Pea

This small, native bean can be frequent in sand prairie remnants. It is unusual in that the pinnate leaves are mildly sensitive, and when touched or jostled the leaflets gradually close. This phenomenon happens very slowly and is difficult to see in action.
The leaf petioles each have a nectar-bearing gland that is visited by a wide variety of insects. Photographed at Liverpool Sandpits Nature Preserve in Lake County, Indiana. Long known as Cassia fasciculata, it is now being called either Cassia chamaecrista or Chamaecrista fasculata.

Woodland Sunflower

This attractive composite is very common in Black Oak savannas that are not too shady from fire suppression. It is colonial by elongate rhizomes and its colonies are sometimes quite dense. Like the cultivated sunflower, it is common to see all flowers in a colony facing the same way. This plant sometimes shows up in other types of woodland. Photographed at the Heinze Land Trust's Coulter Preserve in Porter County, Indiana. (Helianthus = sun flower). 

It is a very good idea to use botanical keys and descriptions when identifying wild sunflowers. The trouble with a close-up photo is that the plant's distinctive features often do not show up in the picture. Here is another shot of the same plant shown above, with the following features visible (from the Gleason & Cronquist description)  -stems glabrous below the inflorescence, often glaucous; leaves all opposite, sessile or rarely on a petiole to 5 mm, scabrous above, narrowly lanceolate to broadly lance-ovate, broadest near the truncate or broadly rounded base, tapering to the slender, acuminate tip, shallowly toothed or subentire, trinerved near the base; heads 1-several at the tips of stiff, cymose branches; disc yellow, involucral bracts lance-acuminate or -attenuate; ciliolate, often with deflexed tips (I don't see that, but "often" doesn't mean "always").  I believe it is Woodland Sunflower, Helianthus divaricatus

Monday, August 13, 2012

Button Weed

Also known as "Poor Joe," this little plant in the coffee family (Rubiaceae) can be quite common in dry sandy sites that are open and disturbed. I first noticed it in the mid- 1980's while exploring with Ken Klick and Sandy O'Brien. None of us recognized it, so Ken and Sandy ran it through Swink and Wilhelm's keys to the families and genera. 
They worked together and did this out loud, showing a remarkable understanding of the language of botany and its myriad descriptive terms. They arrived at Diodia teres var. setifera without ever looking at a picture! It was an excellent lesson in the value of botanical keys, the most accurate way to identify an unknown plant. Thanks Ken and Sandy for providing me with the impetus to learn the language of botany all those years ago! Photographed near Knox, Indiana.

Thursday, August 9, 2012

The 3 Wings of Tall Coreopsis

A common native in prairie remnants, Coreopsis tripteris often towers above the surrounding vegetation. 
The leaves appear to be compound with three (or more) leaflets, and most authors treat them this way, but they might be just very deeply lobed.
The specific epithet "tripteris" means "three wings" or "three feathers," perhaps an allusion to the venation of the three leaflets, especially noticeable on the underside. The Latin "pteris" is often used in reference to ferns, again meaning "wing" or "feather."
The word "Coreopsis" will always remind me of the lovable Walter Mitty (see "The Secret Life of Walter Mitty" by James Thurber).

Tuesday, August 7, 2012

Post number 500!

Presenting GYBO post number 500! In celebration, here are my top 10 favorite photos. Probably all of them were posted sometime earlier. Thanks to all who visit and comment, and thanks to all who have posted here. Special thanks to Ben and Scott for setting up this group blog.
Interrupted Fern, Porter County, Indiana

Bloodroot, LaPorte County, Indiana

Blue-Eyed Mary, LaPorte County, Indiana

Cleft Phlox, Lake County, Indiana

Bluehearts, Lake County, Indiana

Prairie Brome, Lake County, Indiana

Nieuwland's Blazing Star, Lake County, Indiana

Yellow Lady's Slipper, Lake County, Indiana

Sullivant's Milkweed, Lake County, Indiana

Wild Columbine, Marshall County, Indiana

Monday, August 6, 2012

Winged Monkey Flower

I found Mimulus alatus quite by accident while searching for another plant in LaPorte County, Indiana. It features leaves with petioles, peduncles less than 1.5 cm long, winged stems, and leaves with teeth that are curved on the back. It was growing in rich, mesic forest in shade.

Pale Touch-Me-Not

Impatiens pallida is common in shady forests in Indiana, especially in places with rich soil. Photographed in LaPorte County, Indiana on August 5, 2012.

Jumpin' Seeds!

"Jumpseed" was long known as Tovara virginiana. It is now called Polygonum virginianum or Antenoron virginianum. It is common in forests in Indiana, and when the fruits are dry, if you grasp the stem between thumb and forefinger and slide slowly upward, the seeds will "jump" away from the plant quite some distance. It is also known as Virginia Knotweed or Woodland Knotweed, but don't be fooled by the name - it is native here.

Saturday, August 4, 2012

Oh, Harry... You So Handsome!

I made a quick stop today at a preserve in LaPorte County, Indiana and was astounded by the size of the population of Rhexia virginica (Virginia Meadow Beauty, aka Prairie Pitchers, or Handsome Harry) in an artificially excavated sand flat.  I've visited this site fairly regularly over the past several years, and this is the first time I've seen Rhexia virginica spread out through most of the sand flat; usually it is just around the perimeter, and sometimes there are just a few plants.  In years with normal precipitation, the sand flat is a pond, at least through the spring.  Maybe the dry conditions this year have benefited Rhexia virginica at this site.

I'm not sure how this species acquired the name "Harry," but the "Handsome" part sure isn't any mystery.  The unique stamens of Rhexia virginica, with the anther attached to the filament at a knee-like joint, release pollen when the wings of a nearby bee buzz at a particular frequency (a phenomenon known as buzz-pollination).  The leaves of Rhexia virginica are very similar to the leaves of other members of the family Melastomataceae (or Melastomaceae), as they are opposite, decussate, and have three veins running their length.  The leaves also have distinctive pubescence, with hairs that stand perfectly upright on their top surface.  The family Melastomataceae is primarily a tropical family, and even in the tropics where plant richness dwarfs that of the Midwest you can quickly recognize a plant from this family just by looking at the characteristic leaves.

Rhexia virginica grows in wet to moist sand in much of the eastern half of North America, with a stronger distribution along the coastal plain.