Sunday, July 24, 2016

Visitng Sweden--A Wandering Botanist in Stockholm part 2

Our trip to the big city of Stockholm, Sweden, turned into a botanical tour as well (link to last week). Here are some more of the pleasures of botanizing in a city.
the Gustav Vasa
the Gustav Vasa
The Vasa Museum is the very famous Stockholm museum housing the ship the Gustav Vasa, a sailing ship that sank in Stockholm harbor in 1628 on its maiden voyage and that, 333 years later, was raised, restored and provides a wonderful glimpse of the time (link). I had seen the museum in 1969 and 1987 but enjoyed it mightily this time too. One engaging addition was a series of videos on the situation elsewhere in the world at the time--I didn't know that at that time the Ming Dynasty in China was being defeated by the Qing (link) or that the Vasa was concurrent with the Mughal empire in India (link).

AND, the Vasa Museum curators had created a garden of plants typically used when the Vasa sailed. I certainly never saw the garden in my previous visits. It is close to the doors to the museum, but not particularly obvious. The little garden featured food plants such as broad beans (Vicia fava) and kale (Brassica oleracea), and medical plants like St. Johns wort (Hypericum perforatum), comfrey (Symphytum officinale), and opium poppies (Papaver somniferum). The flax (Linum usitatissimum) was in full bloom. Flax was grown for flax seeds and the linseed oil produced from them and the stalks were processed into linen. Today there are specialized varieties of flax for each purpose, but that was probably not the case in 1628. I was surprised the flax was so short: turning those little stalks into thread would have been hard work. But all linen production is hard work, because you have to strip the outer layers off the strong central fiber, a process of rotting and pounding, before you can begin to spin.( more on making linen thread).

Flax, Linum usitatissimum, in flower

Sunday, July 17, 2016

Visiting Sweden—A Wandering Botanist in Stockholm

Stockholm, Sweden

Stockholm is the capital of Sweden, a major city with a population of almost 800,000. How is that a botanical destination? 

Well, as soon as you get more than, say, 100 miles from home, the plants start to change because the climate (and soil or both) change. By the time you hop half way around the world (Denver to Newark, 4 hour flight, Newark to Stockholm 7 hours more) the native plants are almost entirely different. Recognizing a plant is exciting!

lawn with yarrow
Lawn with yarrow (Achillea millefolium, sunflower family, Asteraceae) as weeds
There are green trees and green lawns in a city like Stockholm, so it seems familiar. But when I looked more closely, most of the plants were different. Distance--being on opposite sides of an ocean, for example--is important in making different areas have different ordinary plants but climate plays a big part too. In Stockholm it was light until nearly midnight although the sun was very low by then and although the days were sunny the highs rarely topped 80 F. Several nights, it rained. In Colorado while we were gone, most days were over 90 and there was one brief thunderstorm. Plants that do well in the cool moisture of Stockholm are just not the same plants that grow well in the intense dry heat of midsummer Colorado.

Sunday, July 10, 2016

Plant Story--Thyme Lawn

When I retired, I had lots of thyme.

blooming thyme

That's because I removed the grass from my lawn and planted thyme in that space. I reasoned that the front lawn was never needed for a picnic or a croquet game and mowing was tedious. It has worked wonderfully. The small plants I planted have spread to cover all the space:

newly planted thyme lawn
The lawn just after it was planted.

Sunday, July 3, 2016

Visiting Hawaii--Hawaiian Diversity

Hawaii is an island chain in the middle of the Pacific Ocean, about as far from a continent as you can be on our earth. The islands were never part of a continent, they were created by a mid-Pacific volcanic hot spot forcing lava up to toward the surface. The ocean is 19,000 feet deep in that area, but the push from below is persistent: it built islands that not only emerged above the ocean surface but that reach heights of more than 13,000'. The two tall volcanoes on the Big Island, Mauna Loa and Mauna Kea, are both taller than Mt. Everest (29,005') if you count from the sea floor (30,085 and 30,196' respectively.)

That combination of history and isolation makes Hawaii the hardest place for plants and animals to colonize. Botanists estimate that only 290 plants ever made it on their own. They have to have survived drifting in floating debris for weeks, or clung as living seeds to the feet of birds on a long-distance flight or, in the case of the tiny spores of ferns, ridden a storm wind and landed not in the sea but on a tiny bit of land.

ferns growing on new lava

Sunday, June 26, 2016

Sunday, June 19, 2016

Plants with Extrafloral Nectaries

Why are there ants on the peony buds?
ants on peony extrafloral nectaries
Ants taking nectar from peony extrafloral nectaries.
The simple answer is because peony buds secrete nectar (sugar water).
drop of nectar on peony bud
Drop of nectar on peony bud (upper right)
Why do peony buds secrete nectar?

There is no definitive answer to that question, but, based on studies of other plants, to attract ants which defend the plant from damage.

Sunday, June 12, 2016

Plant Story--Peonies from Europe

Its always a joy when the peonies flower!


Europeans have been using two of their five native peonies, the female peony Paeonia officinalis (link) and the male peony P. mascula (link) medicinally for millennia.

It is not obvious today why they are called male and female. It does not reflect the botany. Both are male, in the sense of having pollen (sperm) and both are female, in the sense of having eggs within ovules that develop into seeds. In both species, both "male" and "female" function occur within the same flower (hermaphrodite flowers). Furthermore that explanation is relatively recent--that plants did any kind of sexual reproduction was one of Linneaus' absolutely shocking suggestions in the late 1700s. Peonies were called male and female long before that.


The Bynums in Remarkable Plants suggest that the designation reflects the relative size and vigor of the two plants, male peonies being larger than female peonies.