Virtual Museum of Canada
Jardin botanique de Montréal 
Centre for Forest Research

Transcription of video clip From seedling to tree - Germination

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The first stages of life: pollination and germination

Photo of a conifer's female cones

© Jardin botanique de Montréal (Gilles Murray)
The overlapping scales cover the ovules.

This female conifer cone is covered with overlapping scales that protect the tree's ovules.

When the cone is mature, the scales separate. The exposed ovules are ready to be fertilized.

The male cones release pollen. The pollen grains might be carried by the wind to a female cone.

The grains that fall between the scales will pollinate an ovule.

After fertilisation, several embryos engage in a struggle for the limited nutritional resources. In the end, a single embryo will survive.

The tree then stores nutrients in the future seed. These nutritional reserves are essential to the embryo.
The seed then dries out and enters dormancy. It prepares to be disseminated.

Drawing of a germinating conifer seed

© Dr. Lawrence Jensen
The root pushes down into the soil.

If it lands in a favourable environment, the seed absorbs water.

This is the signal that it is time to sprout.

The growing embryo uses its accumulated reserves.

The root pushes down into the soil, hunting for water. It also serves as a support for the stem.

The stem grows too, pulls the seed out of the soil and drops its envelope it to free its embryonic leaves.
The embryo is no more. It is now a seedling, eventually a tree.

Drawing of a hardwood's flower, after pollinisation

© Dr. Lawrence Jensen
Its ovules fertilized, the flower transforms into a fruit.

In hardwood trees, the pollen adheres to the stigma, a receptive surface of the style of the flower.

Once the ovules have been fertilized, the flower releases its reproductive parts and only keeps the ovary, healthy and firmly attached to the plant. Hormones encourage the ovary to grow.

Inside the ovary, seeds form.
Inside the seeds, embryos.

As with conifers, hardwood trees store nutrients in their seeds and draw water from them. The embryo is plunged into dormancy.
The seed hardens and is dispersed.

Here is the primary root of an acorn that is rooting the seed.
So, from seed to mature oak that will flower: the circle is complete.

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