The wild sweet-pea is just one of many species of wild plants that flowers during the last weeks of winter into early spring and summer without having to wait for a drop of rain to fall.These flowers are termed pre-rain flowers and accumulate water and other resources during the previous year's growing season. Often, late winter fires act as a trigger for wild flowers of this kind to develop rapidly and flower before being engulfed by grasses, which effectively limit the chances of pollinators noticing and pollinating them.

One of the most interesting aspects of the floral anatomy of Sphenostylis angustifolia is the distinct orientation (handedness) of the style which is the female part of the plant reproductive structure. It is turned in a distinctly right- or left-handed way as it protrudes from the floral base, even forcing the keel to grow in the specific direction of orientation.

Until recently, there were only speculations as to why some plants display this orientation, which can also be seen in leaf arrangement and tendrils, but very little data has been available to back up the theories. It has since been found that there is a genetic basis for this phenomenon. This occurrence is thought to be a mechanism plants use to prevent self- fertilization. This difference in floral orientation prevents the pollen of right-handed flowers from being introduced to other right-handed flowers and vice versa for left-handed flowers. Rather, the pollination of the opposite type of flower is promoted, thus encouraging cross-pollination between plants. By preventing self- fertilization, plants increase their genetic variability which is beneficial during adverse environmental conditions and in cases of plant pathological conditions. Even though this theory holds for plants of other species, it still doesn't explain the dominance of right-handed flowers of the wild sweet-pea as observed in nature.