Tuesday, September 1, 2015

Mother Nature's Gardens

Around here, it's the spring wildflowers that get all the attention. We have had a Wildflower Pilgrimmage up in the Great Smoky Mountains National Park for decades. One reason for the intense interest lies in the amazing diversity of our spring flora, with numerous families from orchids to aroids represented.

The fall flower show is a little bit different. For one thing, most of the flowers are from a single family, the asters. For another, you don't have to drive to the Park in order to enjoy the display. Some of our most spectacular fall bloomers thrive in roadside ditches, open fields where the soil has been disturbed, and at edges where development meets the woods.

Just for fun, yesterday I did a little survey of the plants that are presently blooming between my house and the grocery store I frequent, a distance of about 1.2 miles. Much of the area is covered with asphalt or buildings, but there is a huge open space (intended for future development) lying between the county road and the Interstate. It is along the edge of this space that the majority of the flowers can be seen, and the diversity of species is such a small area is remarkable. Here is my list:

Asters (Aster sp.)--Notoriously difficult to identify to the species level, there appears to be at least two species

Goldenrod (Solidago sp.)--Another group of species that are difficult to separate, this one is probably S. rugosa, or common rough goldenrod

Ironweed (Vernonia noveboracensis)--Among the most intensely purple blooms to be found in the plant kingdom, this tall plant thrives in moisture-retentive soils.

Tickseed (Coreopsis)--Bearing bright yellow blooms with notched petals, this plant has been domesticated to produce numerous cultivars.

Calliopsis (Coreopsis)--This group of plants was once a separate genus, but now is considered part of the Coreopsis species complex. The yellow blooms often have bright red centers. It is another example of a wildflower domesticated for the garden.

Black-eyed Susan (Rudbeckia hirta)--This roadside perennial is the parent of 'Goldsturm' and numerous other cultivars for the garden.

Joe Pye weed (Eutrochium)--The most common species in North Knoxville appears to be E. maculatum, or spotted Joe Pye weed.

Snakeroot (Eupatorium)--This plant is similar to Joe Pye weed, but the flowers are pure white, whereas Joe Pye is a dusty rose color.

Sunflower (Helianthus)--The ones in my area are probably H. tuberosus, the perennial also known as Jerusalem artichoke.

Cockleburr (Xanthium)--Always considered a weed, owing to its spiky fruits, this plant produces pale yellow female flowers that look rather pretty at a distance.

Ragweed (Ambrosia)--Despite the connotations of its botanical name, this plant is responsible for a large number of seasonal allergy problems, often known as "hay fever." Please note that the other asters mentioned here do not produce lots of wind borne pollen, and therefore do not perpetrate allergy reactions in humans. Too often, goldenrod or one of the other fall blooms gets the blame, while the real culprit, ragweed, with its insignificant greenish-yellow flowers goes unnoticed.

Cardinal flower (Lobelia cardinalis)--Bright red bloom spikes appear all summer long where the soil stays moist. This plant is common along an I-75 drainage swale near the house.

Everlasting pea (Lathyrus)--An established exotic weed, this plant had lovely pink and white flowers for most of the summer. It used to be cultivated, but has proved too invasive for the garden.

With the exception of the last two, all these plants are asters.

As the vegetable garden winds down and your summer annuals begin to look a little ratty, take a moment to enjoy the floral display along our Tennessee roadways during this late summer season. If you are traveling in the Cumberland Plateau region, you may see several others, such as meadow beauty (Rhexis), in addition to the ones named above.

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