The Botany of Valentine's Day: If people reproduced like plants

If people were like plants, in-vitro fertilization would be the norm. Most plants rely on a third party, such as an insect or bird, to help them reproduce. The animal removes pollen from the stamens of one flower and transfers it to the pistil of another flower. Humans also sometimes fill this role, hand pollinating crop plants like vanilla (Vanilla planifolia) when insect pollinators are not available.

If you couldn’t find a mate and really wanted to have a baby, you could just fertilize yourself! The baby would be a clone that is genetically identical to the mother. Many plants can fertilize themselves in case they are not visited by pollinators. Self-fertilization isn’t ideal as inbreeding can produce individuals that are less healthy but at least all the effort spent producing eggs and pollen is not completely wasted.

Image: This bumblebee (Bombus) is fertilizing a breadroot (Pediomelum esculentum) plant. The bee gets paid with a delicious drink of nectar.

If people were like plants everyone would have several thousand children every year. Unfortunately, about half of them would be eaten by lions; seed predation is high in plants with 40-50% losses to birds, rodents, and insects being common. The seeds that do survive might spend decades living in a vegetative state before resuming a normal life and reproducing; this is sort of like having teenager who does nothing but play video games all day. The oldest seed ever successfully grown was a Judean date palm (Phoenix dactylifera) that was about 2,000 years old. Talk about a failure to launch!

So when you’re purchasing or appreciating your Valentine’s Day flowers this year remember that at the very least, the plant has gotten lucky!

Why did people think Manitoba and Saskatchewan so unsuitable for farming?

Peoples’ impressions of the prairie were largely based on a report by Captain John Palliser who travelled through the southern prairies from 1857 to 1860. Palliser described an area in southwestern Saskatchewan and southeastern Alberta as being a desert but he did have some good reasons to call it that. Palliser travelled through the area during a severe drought. His route took him through several large active sand dune complexes. Migratory Bison were still grazing the area and keeping the grasses short. To top it all off he encountered several large grass fires in the area. So the mixed grass prairies would have looked fairly desert-like at the time.

Image: Captain John Palliser travelled through dry, desert-like areas in western Canada during a drought.

What was his conclusion as to how fertile the land was and it’s suitability for agriculture?

Most Canadians were accustomed to farming under wetter conditions or using irrigation, as most were originally from wetter areas in Europe like England, Scotland, and France. They didn’t have much experience with dryland farming so they considered the prairies too dry for agriculture. Macoun recognized that adequate soil moisture is usually present in the spring when wheat needs it the most so he thought that cultivation of this crop was possible. Unfortunately, he underestimated the frequency and severity of droughts and during the dirty 1930s much of the farmland in the driest areas of the prairies was abandoned.

Did the government act on his report?

They sure did! Politicians were very eager for settlement to occur in the southern prairies as they were concerned about American expansion into Canada. They also wanted the wealth that would be created if farmers were to grow crops for export. So the Canadian Government launched an advertising campaign to encourage mostly European immigrants to settle the prairies.

Image: The Canadian Government tried to lure European settlers to the prairies with posters such as this one.

Not much later she was preparing yet another Waxwing with a broken beak. This one had lots of ground up orange-coloured flesh inside the crop. The colour of the fruit made me think about an incident that happened long ago. One winter day I came across a huge flock of Waxwings gently pipping in a tree. I paused to admire them and was puzzled to hear an unusual plunking sound. I looked at the snow under the tree and saw that it was covered with orange-coloured poop from the mountain ash (Sorbus  sp.) berries the Waxwings were eating. The plunking sound was that of bird poop landing in the snow. Furthermore, I was standing directly in the line of fire! Admiration quickly turned to panic and I dashed out of target range. A quick examination of dried mountain ash berries in our collection helped me confirm my educated guess.

Image: Mountain ash (Sorbus sp.) tree with green fruits. The fruits turn bright orange when ripe.

The life cycle of mosses is quite different from that of flowering plants and people. If humans reproduced like mosses, our babies would grow out of our heads! Flowers and people normally have two sets of gene-containing chromosomes. Within our sex organs, cells with only half of these chromosomes are produced, namely eggs and sperm. This occurs so that when an egg and sperm unite, there will be just two sets of chromosomes (not four), one from each parent. But in mosses things work a little bit differently.

Mosses are like the amphibians of the plant world: they still need water to reproduce. The main part of the moss, the leafy green part, has only one set of chromosomes. During a wet time of the year, often spring, these plants produce eggs and sperm by straight cell division at the tips of their stems. The sperm are released and have to swim through water to reach the eggs. Once a sperm reaches an egg and fertilizes it, a tiny structure starts to grow from the tip of stem: a sporophyte with two sets of chromosomes. The sporophyte eventually produces spores with only one set of chromosomes. Once released, the tiny spores germinate and go on to produce the little plants we all know so well. Finished with its job of making babies and unable to photosynthesize, the sporophyte simply withers and falls off.

Image: It’s not dead! It’s just resting! Dried up mosses, like the ones on this rock, cease to be biologically active during hot, dry periods.