1. It exhibited characters that are constant and easily recognizable such as texture of seed, height or stature, color of specific plant organs, etc. ;
2. Some forms of the genus exhibited contrasting traits such as smooth vs. wrinkled seeds, short vs. tall height, axillary or terminal flowers, etc.;
3. Hybrids and their offspring are fertile, that is, continuous cross- and self-fertilizations were possible and the seeds maintained viability;
4. It is highly naturally self pollinated because the reproductive parts of the flower are covered by the keel (petals) which only opens after pollination has been completed. This phenomenon is now called cleistogamy;
5. These plants are easy to grow either on the ground or in pots;
6. The plants have short maturity; and
7. Although the cross pollination methods are somewhat complicated, the results are largely successful. The procedure consisted of the opening of the young bud, removal of the keel, removal of the stamen using forcep (emasculation), and dusting of the stigma with the pollen from the specified parent plant.