Botanical illustrators and those practising science art have to understand the biological terminology that applies to their subject matter. All of my illustrations for this blog are taken from The Garden Forager by Adele Nozedar (publ. 26.03.2015). Follow the link to see all of them on my Pinterest site.
Following on from September's blog about Basic botanical terms; this week I'm going to explore the importance of the ovary in knowing what flower you're looking at or illustrating. First, a swift recap of basic botany.
The flower's ovary contains the unfertilized seeds, or ovules. Protruding from it is a tube called a style, with an area at its tip called the stigma. This is where pollen hopes to land so it can burrow down to access and fertilize the ovules, thus creating seeds.
Working out from the centre of a flower; outside the female reproductive parts (the gynoceium) are the male reproductive parts (stamens and the flower part which bears them, known together as the androecium); then the petals and sepals which aren't involved in plant sexual reproduction. These petals and non-reproductive parts of a flower are known as a perianth.
Right. Onto the position of the ovary. Here's a diagram (modified from Swink and Wilhelm, Plants of the Chicago region 1994).
On first sight it looks complicated, but actually this is one bit of botanical terminology that's really straight forward.
Plants can be classified depending on where their ovary sits in relation to the rest of the bits of the flower. As you'd expect, there are three possibilities here; namely a superior ovary (where the ovary attaches to the receptacle ABOVE the attachement sites of the other parts of the flower); an inferior ovary (where the ovary attaches to the receptacle BELOW the attachment sites of the other parts of the flower); and a middling one, the half-inferior ovary (where the other parts of the flower attach to the ovary on the SAME LEVEL as the flat or concave receptacle.) And a receptacle is the part of the plant to which all the parts of the flower are attached.
Examples of plants with a superior ovary include the mallow (Malva sylvestris) (look closley at my longditudinal cross section and you can clearly see the ovary sits below the petals).
Another plant with a superior ovary is borage (Borago officinalis). Again, where I've illustrated the seeds, you can see how the rest of the flower parts grew below this site.
Other plants sporting superior ovaries include the buttercups, grapes, black pepper, geranium, tomato and in fact all plants which produce true berries and drupes (see my blog on Fruit type terminology).
All these plants with superior ovaries are said to have hypogynous flowers, or to be hypogynous. This just means they have superior ovaries. Let's continue.
Next up is the half-inferior ovary (also known as “half-superior”, “subinferior,” or “partially inferior,”- Wikipedia). The flower parts in these examples are surrounded by the receptacle, or embedded into them. The first example is the rose (Rosa).
Have a close look at a rose. The stamens, petals and sepals are all pretty much on the same level in terms of where they attach to the green receptacle. When the rose develops a rosehip you can see the flower remnants arent at the very tip, but a little lower down. A half-inferior ovary.
Another example is the passion flower (Passiflora).
Passion flowers are quite mad to draw, but with all the flower parts so large it's clear that their insertion points are neither above or below the receptacle, but on the same plane. Half-inferior ovary. Other examples incluse Pyracanthus (on close examination) and some of the Lythraceae family.
Plants with half-inferior ovaries are referred to as perigynous flowers, or being perigynous.
Last up are plants with inferior ovaries; where the ovary sits neatly below the point of attachment for the other parts of the flower. An example of this is the fucshia (Fucshia spc).
In this illustration, you can see from the cross section that the ovary lies below the rest of the flower. It's even visible in the colour study; the darker region below the petals encloses the ovary.
Other examples include the orchid family, and some members of the Asteraceae family (my blog has more on Composite flowers). Each individual disk and ray floret bears an ovary at its base, an inferior ovary; these mature into seeds known as cypselas (a type of achene, for more on achenes read my blog). Just think of a dandelion seed. All the fluff at the top, the seed very firmly below all the rest of it. An inferior ovary.
This chicory flower shows the blue petals (corolla) and stamens above the brown receptacle which encloses the ovary below.
Plants with inferior ovaries are said to bear epigynous flowers, or to be eipgynous.
To be honest, at first when I researched this topic my blood ran cold as the latin terms washed round my brain; but actually I hope I've shown that ovary position and the latin terms used to describe this are quite straight forward. My botany bible for definitions is Flora of the British Isles by Clapham, Tutin, and Moore. However, I do want to point out that i'm an illustrator not a botanist, so if you find mistakes in these botany blogs, please get in touch and let me know so I can fix them.
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