Flowers that are both fragrant and colorful are uncommon only because each tactic uses resources. Concentration of effort into one method of appeal or another is more efficient. Diversification generally occurs among flowers that must compete for pollination within a very diverse ecosystem. Otherwise, most fragrant flowers prefer selective specialization.
Consequently, most of the most fragrant flowers are not remarkably colorful. In fact, some are visually mundane. Where they mingle with more prominent bloom, the more visually evident flowers are likely to get credit for ambient aroma. Although many fragrant flowers are bright white, many more are uninterestingly pallid white. Some can be difficult to find.
They are no less specialized than more colorful flowers, though. Dispersion of fragrance coincides with pollinating activity of preferable pollinators. It is no coincidence that many fragrant flowers are most fragrant in the evening or night for nocturnal pollinators who do not pursue color. Some pollinators may appreciate minor ultraviolet or infrared markings.
Also, fragrant flowers customize their fragrances for their favorite pollinators. That is why floral fragrances are so distinctive. Hummingbirds and most insects prefer rich fragrance during the day. Bats and nocturnal moths prefer sweeter fragrances of nocturnal flowers. Humidity and warmth enhance the activity of most pollinators, as well as floral fragrance.
Fragrant spring bulbs, wisteria, lilac, mock orange and pink jasmine finished blooming in spring. Star jasmine, night blooming jasmine and various pittosporum should continue to bloom sporadically and fragrantly as long as the weather is warm. Sweet osmanthus and sweet box are a bit less fragrant. Gardenia, although finicky, is famously overtly fragrant!