In the world of plants, "species" refer to naturally occurring groups of plants that share common characteristics and can interbreed to produce viable offspring. For instance, the common dandelion belongs to the species Taraxacum officinale. Plants generally exhibit similar appearance and growth habits within a species while displaying a natural range of variation.

On the other hand, a "cultivar" is a plant that has been deliberately bred and selected for specific desirable traits, such as color, size, shape, or disease resistance. Cultivars are created by repeatedly choosing and propagating plants with these sought-after traits, resulting in distinct varieties separate from their parent species. Each cultivar is given a unique name to differentiate it from other plants, often incorporating the name of its creator or the location of its development.

To summarize, straight species are naturally occurring plants found in nature, unaltered and not intentionally modified for specific traits. In contrast, cultivars are consciously developed through selective breeding for particular attributes, creating distinctive variations.

Let's consider the classic rose as an example to compare the two. The straight species, Rosa species, have a more natural appearance and often grow wild. Cultivars, on the other hand, have been specifically bred to exhibit desired qualities like unique colors and fragrances, and they are given specific names like "Double Delight" or "Peace."

Regarding ecological benefits, straight species have advantages as they preserve the genetic diversity and ecosystem relationships that have evolved naturally over time. They can provide essential habitat and food sources for local wildlife. However, cultivars can also offer ecological benefits when selected for traits that support pollinators or are better adapted to local environmental conditions.

Ultimately, the choice between straight species and cultivars depends on personal preferences, design goals, and the specific needs of each gardening or landscaping project. Gardeners and landscape designers can opt for a mix of both to create beautiful, functional, and ecologically beneficial spaces.