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MAGNOLIA BLOSSOMS

Flower of Southern Magnolia, Magnolia grandifloraThe blossom at the right, from a Southern Magnolia, Magnolia grandiflora, growing next to my home, is about 8 inches across (20 cm) and as I made the image the blossom filled the air around me with a powerful, lemony fragrance. Magnolia flowers are wonderful!

Magnolia blossoms grow at the end of a tree's branches. They possess 3 sepals and 6-12 petals. You may have problems finding this species' sepals, however, because they look like the petals.

People who study the evolution of flowering plants say that magnolia flowers are similar to some of the very first flowers. They're not the most primitive surviving flower type (waterlilies are often thought to be more primitive), but they're very, very primitive.

cross section of magnolia flower showing stigmas and stamensAmong the magnolia blossom's primitive features are the facts that, in contrast to our Standard Blossom,  they bear many stamens and many pistils. The stamens are arranged in spiraling rows, and both stamens and pistils are attached to a fingerlike receptacle. To understand why these features are considered primitive, you need to know a lot of technical stuff we can't go into here. However, one easy thing to understand is that some of the oldest fossil flowers discovered are similar to magnolia blossoms.

In the picture at the right showing a cross section of the above flower, consider the fact that toward the top of the picture you see many curled stigmas, and that each of those stigmas is attached to its own pistil. In other words, the fingerlike receptacle bears many stamens at its base, and many pistils at its top. Each of those pistils will mature into a follicle. A follicle is a dry fruit that opens along one side, and develops from a single pistil. Well, this is allowed, since we've seen that there's a kind of fruit called an aggregate fruit which is composed of several to many stuck-together, ripened pistils, all developing from a single blossom. Magnolias flowers produce aggregate fruits, just like blackberries -- except that blackberry fruits are fleshy, while magnolia fruits are dry.

ovules inside magnolia gynoeciumThe picture at the left shows a cross-section of the center of an immature magnolia flower before it opened -- while it was still a flower bud. The whole thing is about as wide as your finger is thick. Can you see some of the pistils' ovules, which will mature into seeds? The ovules look like tiny eggs inside pale compartments. Each of those pale compartments, or carpels, is connected to an immature stigma. Each magnolia pistil has just one fingerlike stigma and one carpel, and each carpel contains only one or two ovules. Less primitive flowers typically have branched stigmas and more than one carpel per pistil.

magnolia fruitAt the right is a picture of a magnolia fruit. The red seeds, which once were the tiny ovules shown in the last picture, emerge from splitting follicles, which once were pistils. Atop each follicle you can see the dark, dried-up remains of the stigma. This is a classic aggregate fruit.

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