Tuesday, July 22, 2014

Take the time to watch a flower become a fruit

It's well worth it.  It will cement in your consciousness the connection between flower and fruit.  And since every flowering plant is a little different, you learn a little more with each one you watch.

Flowers have a great variety of forms, but we have to start somewhere!
Image: Amer. Museum of Natural History 

The fruit--a closed container around the seeds--is what sets flowering plants apart from other plant groups such as conifers, ferns, etc.  The fruit develops from the ovary (containg ovules that will become seeds) at the base of the pistil (female part) of the flower.  Along the way, most other flower parts, such as stamens (male) and petals fall off.  (Some parts may remain: the five little triangles at the end of an apple are the sepals that originally covered the apple flower bud.)

Fruits come in tremendous variety.

The "seeds" (really fruits) of grasses in many cases look much like the flowers, such as the deertongue grass (Panicum clandestinum) in my "prairie garden."

The shape of other fruits can be hard to predict from the flower.  Here is the red maple (Acer rubrum) I watched in the spring.  The first photo is male flowers, the rest are female flowers/fruits of increasing age.

Often you can see several stages at the same time, in flowers of different ages on the same or neighboring plants. 

Here is common milkweed (Asclepias syriaca) in my "prairie garden."

Plainly only a few flowers in each cluster produce pods; the rest die or their pods are aborted.
In the fall each pod will mature and split open to release hundreds of flat seeds, 
each floating on the wind below a spray of silken fibers.

Sometimes you can see a gradual process so that the end result is predictable.  Pokeweed* is an annual weed that produces dark, juicy berries that begin as tiny, berry-shaped ovaries.  (In flowering plants, the ovary is the base of the pistil--i.e. female flower part--and contains the ovules that will become seeds.  I think botanists borrowed the term by analogy from animal anatomy.)

The ovary shows at the center of the open flower.  It looks like a miniature berry.

Some flowers can be hard to "catch in the act" of becoming fruits, such as dandelion and Queen-Ann's-Lace, which close up and transforms "in secret."
Dandelion (Taraxicum officinale) flower at left, closed at right, open once more with mature fruit in center.
Image from http://www.washingtonpost.com/wp-srv/special/metro/urban-jungle/pages/110419.html

The flower cluster of Queen Ann's Lace or Wild Carrot (Daucus carota) closes to form
 a "bird's nest," before making the bristly little fruits you can just make out in bottom photo.

Look at a few kinds of flowers in your neighborhood.  Visit them every few days and watch them change!

*Pokeweed, Phytolacca americana, is the only plant I know that is sometimes listed as poisonous, yet appears in old cookbook recipes for "pokeberry pie."

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