White roses are a universal symbol of new beginnings and reverence, possessing a quiet elegance that has secured their place in gardens and floral arrangements for centuries. The diversity in form and habit among white roses is immense, with countless named varieties developed for specific uses, from landscaping hedges to elegant cut flowers. Understanding what a white rose is “called” requires navigating the horticultural system that organizes these unique plants by their growth characteristics and genetic heritage.
Understanding Rose Classifications
Horticulturists categorize roses into broad groups based on their growth structure and flowering patterns. The Hybrid Tea is perhaps the most recognizable classification, characterized by large, shapely blooms borne singly on long, upright stems, making them the classic florist’s rose. In contrast, Floribunda roses produce flowers in large, dense clusters, offering continuous color on shorter, bushier plants.
Shrub roses represent a versatile and robust category, typically growing larger with a dense, branching habit suitable for hedges and background plantings. This group includes English Roses, modern hybrids that combine repeat-flowering and disease resistance with the deep cups and strong fragrance of old-fashioned varieties. Climbing roses feature long, flexible canes that require support to grow vertically, allowing cultivars to cover trellises, arches, or walls.
Iconic and Popular Named Varieties
The most widely planted white rose is the Floribunda known as ‘Iceberg’ (Rosa ‘Iceberg’), a variety celebrated for its exceptional vigor and continuous, prolific blooming. This cultivar forms a dense, bushy shrub covered in medium-sized, pure white flowers in large clusters. It is highly valued for its good disease resistance and light, honey-like fragrance. Its dependable performance makes ‘Iceberg’ a popular choice for mass plantings and hedges in diverse climates across the globe.
The Hybrid Tea ‘Pope John Paul II’ produces exceptionally large, luminous white flowers, often measuring over five inches across. This variety is intensely fragrant, emitting a powerful citrus scent, and is highly prized as a cut flower. Its blooms are typically borne one per stem on long, sturdy canes. The plant grows with an upright, narrower habit compared to bushy Floribundas, embodying the classic exhibition-quality rose form.
Another celebrated white cultivar is ‘Tranquility,’ a Shrub rose bred by David Austin that exhibits the densely petaled, deeply cupped shape of old garden roses. This English Rose opens from pale yellow buds to large, creamy white blooms with a strong apple-like fragrance. The shrub grows to a medium height with a pleasingly rounded structure. ‘Tranquility’ offers repeat flowering and improved health compared to its antique ancestors, making it a good choice for mixed borders where an old-world aesthetic is desired. Similarly, the English Shrub rose ‘Winchester Cathedral’ is a sport of a pink variety, offering quartered white blooms that age to a soft cream, known for its musky, sweet fragrance and vigorous, upright growth habit.
How White Roses Get Their Color
The pristine color of a white rose is due to the absence of the chemical compounds that create other hues, not the presence of a white pigment. Flower color in roses is primarily determined by two classes of pigments: anthocyanins (reds, pinks, and purples) and carotenoids (yellows and oranges). White roses lack the necessary genetic machinery to produce these colored pigments in their petals.
The petal cells contain mostly colorless flavonoids, such as flavones, which absorb ultraviolet light. The white appearance we perceive is created because the petal cells reflect all visible wavelengths of light equally. Tiny air spaces within the petal tissue can also contribute to this effect, causing light to scatter and resulting in a brilliant, pure white color. This mechanism of light reflection, rather than pigment deposition, is the biological basis for the rose’s snowy hue.