The other species are all propagated by their cleistogamous flowers.
The genus Viola is an advanced species: it would therefore seem that the production of cleistogamous flowers is an advance on the production of entomophilous flowers.
It is significant that some plants produce cleistogamous flowers, that is to say, flowers which invariably fertilise themselves.
In England, where this jewel-weed is rapidly becoming naturalized, Darwin recorded there are twenty plants producing cleistogamousflowers to one having showy blossoms which, even when produced, seldom set seed.
Sometimes the flowers are cleistogamous (see violet wood-sorrel).
In addition to its showy blossoms, which so successfully invite insects to transfer their pollen, thereby counteracting the bad effects of close inbreeding, the plant bears inconspicuous cleistogamous or blind ones also.
This species produces no cleistogamous or blind flowers.
Abundant cleistogamous flowers (see blue violets and white wood sorrel) are borne on the runners late in the season.
This species produces an abundance of late cleistogamous flowers on erect stems.
If it were only a question of producing seed in the simplest way, cleistogamous flowers would be the most conveniently constructed.
Conditions of nutrition in the broader sense are the factors which determine whether chasmogamous or cleistogamous flowers are produced, assuming, of course, that the plants in question have the power of developing both forms of flower.
His view that cleistogamous flowers are derived from originally chasmogamous flowers has been confirmed by more recent researches.
Some of the plants with cleistogamous flowers might afford examples of such cases.
These cleistogamous flowers afford a striking example of habitual self-pollination, and H.
The second are cleistogamous ones (fertilized in the bud) on short curving peduncles from the root.
Most of the Violets, during the summer, have apetalous or cleistogamous flowers on short peduncles from the root; these never open, but are fertilized in the bud.
But close fertilization is inevitable in what are calledCleistogamous Flowers, that is, in those which are fertilized in the flower-bud, while still unopened.
Every plant which produces these cleistogamous or bud-fertilized flowers bears also more conspicuous and open flowers, usually of bright colors.
Two explanations have been suggested of the origin of these cleistogamous flowers: according to the one, they are the earliest form of the flowers; according to the other view, they are degraded forms of the more beautiful flowers.
Recent observation shows that thesecleistogamous flowers, as they are called, are present in a great variety of plants.
In other cases precautions are taken to prevent cross-fertilisation, as in the numerous cleistogamous or closed flowers.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "cleistogamous" in a variety of sentences. We hope that you will now be able to make sentences using this word.
