from The American Heritage® Dictionary of the English Language, 5th Edition.
- adjective Consisting of two parts or segments, as the tarsus in certain insects.
- adjective Botany Having flower parts, such as petals, sepals, and stamens, in sets of two.
from The Century Dictionary.
- Consisting of or divided into two parts; bipartite.
- Specifically In botany, having two members in each whorl: said of flowers. Sometimes written by botanists 2-merous.
- In entomology, having two-jointed tarsi; specifically, pertaining to the Dimera.
from the GNU version of the Collaborative International Dictionary of English.
- adjective Composed of, or having, two parts of each kind.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- adjective botany in two parts: in a flower each whorl (of flower parts) has two flower parts.
from Wiktionary, Creative Commons Attribution/Share-Alike License
Again, it may be remarked that many of these orders show a tendency towards a regular diminution of the assumed normal number of their parts; thus, among _Onagraceæ_, _Circeia_ and _Lopezia_ may be referred to, the former normally dimerous, the latter having only one perfect petal.
So in fuchsias, a very common deviation consists in a trimerous and rarely a dimerous symmetry of the flower.
Regular dimerous flower of _Calanthe vestita_ 402 199.
Regular dimerous flower of _Odontoglossum Alexandræ_ 402 200.
The style is longer than usual, is straight and erect; the broad, disciform stigma therefore faces upwards; it is oval and symmetrical, and a light groove across its middle shows it to be dimerous.
Eichler himself believes that the flower is dimerous, the four longer stamens being produced by the doubling or splitting of the upper (i.e. antero-posterior) pair of stamens.
Darwin afterwards gave a doubtful explanation of this, and concluded that the ovary is dimerous.
Here, therefore, is a symmetrical and complete, regular, but dimerous orchideous flower, the first verticil of stamens not antheriferous, the second antheriferous, the carpels alternate with these; and here we have clear (and perhaps the first direct) demonstration that the orchideous type of flower has two stamineal verticils, as Brown always insisted. "
-- Regular dimerous flower of _Calanthe vestita_.] [Illustration: FIG.