Tuesday, May 28, 2013

Iris versicolor

Dr. Edgar Anderson

Origin of species via hybridization

In the 1920s and 30s Dr. Edgar Anderson of the Missouri Botanical Gardens (MOBOT) and Associate Professor of Botany, Washington University of St. Louis made extensive field trips to examine the variation of form and structure in Iris versicolor, common blue flag. He diagrammed the great amount of genetic variation in natural populations. He found two species rather than one and began to examine how one evolved from the other. His conclusions found more variation within populations of one species than differences between the two species; another species had been involved in the evolution of Iris versicolor. The answer was through hybridization followed by chromosome doubling to produce a fertile, stable, true-breeding amphidiploid. (Melding of the complete chromosome set from each parent.)  His data included chromosome counts and concluded that Iris versicolor (2n = 108), was the amphidiploid progeny of Iris virginica (2n = 70) from the Mississippi valley and Iris setosa var. interior (2n = 38) of the Yukon. Today I. versicolor occurs almost entirely in territory that was covered by ice during Pleistocene glaciation; while I. virginica occurs in untouched areas south. I. setosa var. interior currently growing northwest of the glaciated area, was pushed south by glacial formation into the range of I. virginica. For more information regarding Dr. Anderson visit: http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/anderson-edgar.pdf
Dr. Edgar Anderson
Every year of the past decade I have yearned to follow the footsteps of Dr. Anderson following the bloom season up the Mississippi valley. I have wanted to examine the implications of 90 years and 200 million more humans affecting the environment colonized by Iris versicolor. It could also prove useful to collect variation where it still exists to aid hybridization efforts.

Iris versicolor and I. virginica have always been appreciated for their beauty and medicinal qualities. On the practical side these irises are now included in rainwater gardens and vegetative filter strips. Scientific analysis identified these plants as hyperaccumulators, removing pesticides from soils and able to reduce levels of commonly and widely used insecticides and fungicides.
A principle example of the origin of species, of growing practical and aesthetic value, this iris deserves our foremost consideration.  

Sunday, May 19, 2013

Philadelphia Vireo

Yesterday, prior to a spring thunderstorm a few migrating Philadelphia Vireo visited our flowering plum. The flowers attracted pollinating insects which attracted the vireos.

Philadelphia Vireos are very acrobatic, they hovered before the flowers,
and hung upside down to feed.
These vireos will move into Canada.
A couple severe thunderstorms have destroyed the blossoms today, the vireos were our visual climax!


Wednesday, May 1, 2013

Spring Arrives!

Martagon Lily
Standard Dwarf Bearded Iris

Spring has turned briefly, four days of weather over 60 degrees with a good evening rain. The garden has responded quickly;  martagon lilies are pushing through the surface. Columbine have unfurled green leaves. Sedums dormant through the winter have begun to increase, Standard Dwarf Bearded Iris have doubled in size preparing to flower in a few weeks. Bearberry, evergreen under the snows flush green losing their reddish winter tints. Rhubarb has erupted and their leaves have begun to unfurl, cannot wait to taste the tart stalks.

Martagon lily out of the ground.
The forecast for Thursday is one to two inches of snow with rain, nighttime temperatures in the low 30s; the jet stream has dipped into the northern states. As the sun rises in elevation throughout spring the jet stream controlling our current weather pattern will swing into Canada.

Columbine sprouts quickly.

These perennials are very hardy and I do not worry for their condition. This week’s weather will continue to delay the season and when given the right conditions plants will quickly respond in a rush to increase and then flower. If climate conditions remain cool, iris for example will be slightly shorter than typical bloom heights and colors will be more intense.

SDBs double in size

Sedums increase
Above average snows and rain will be very beneficial. The Mississippi flows a few miles from my home. This fall channels of the river were dry, this is very rare. Water tables will become replenished.
I have delayed planting stratified seed, I want temps to average 50s nighttime and 70s by midday. Watching seed germinate and the first bloom of new cultivars is the greatest events of spring.

Bearberry turns green out from under the snow