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What is the name of the dark purple iris?

Irises come in a wide variety of colors, ranging from pale blues to vibrant yellows. However, one of the most striking iris colors is a deep, rich purple. So what is the name of this dark purple iris variety?

Quick Answer

The dark purple iris is commonly called the purple iris or dark purple flag iris. Its scientific name is Iris germanica ‘Purple Flare’.

What Makes the Purple Iris Dark Purple?

The deep purple color of the purple iris comes from anthocyanin pigments. Anthocyanins are water-soluble pigments that produce blue, purple, and red colors in plants. The specific anthocyanins that create the rich purple color in irises are called cyanidin and peonidin.

These pigments are concentrated in the sepals of the iris flower. The sepals are the three large, spreading outer petals that surround the smaller inner petals. The high levels of anthocyanins in the sepals give them an intensely dark purple color that is the signature of the purple iris variety.

Genetics of the Purple Iris

One reason the purple iris displays such a saturated royal purple color is genetics. This variety has been selectively bred to maximize anthocyanin production in its sepals. The parent plants were likely selected over many generations for increasingly dark purple sepals.

In addition, the pigment production in irises is controlled by several genes. Specific alleles, or variants, of these genes interact to generate high cyanidin and peonidin levels. The purple iris has an ideal combination of anthocyanin-promoting alleles to produce its trademark hue.

Growing Conditions for Deep Purple Color

In addition to genetics, growing conditions can also influence color saturation in irises. Cool spring temperatures, bright sunlight, and slightly acidic soil create ideal conditions for anthocyanin synthesis. Therefore, purple iris plants grown in the proper habitat tend to display richer, more vibrant purple sepals.

Conversely, plants exposed to heat stress or alkaline soils often appear faded and less intensely colored. For the richest purple tone, iris growers should aim to mimic the ideal spring-like conditions.

Distinguishing Features of the Purple Iris

In addition to its regal purple sepals, the purple iris has several other distinguishing features:

  • Blooms in late spring to early summer
  • Sepals have white and yellow markings near their base
  • Flowers grow on tall, straight stems, up to 4 feet tall
  • Narrow green leaves with white variegation
  • Fragrant floral scent
  • Perennial that forms clumping rhizomes
  • Prefers full sun and well-drained soil
  • Zones 3-9

Purple Iris Cultivars

There are a few popular cultivars, or cultivated varieties, of the purple iris:

Cultivar Description
Purple Flare Intensely purple sepals with bright yellow beards
Illustrious Vibrant violet-purple flowers with white dotted sepals
Majestic Royale Very dark purple blooms on tall sturdy stems

These cultivated varieties offer slight variations in flower form and color intensity but share the regal deep purple sepals.

Uses in the Landscape

Thanks to its vivid purple blooms, this iris variety adds a striking pop of color to spring gardens and landscapes. It pairs beautifully with softer-hued plants like pink peonies, white foxgloves, and pale yellow roses.

The tall purple flower stalks can be used as excellent architectural elements. Plant groupings of purple iris in perennial borders, cottage gardens, or along pathways. The color will draw attention while the height adds interest.

This iris also works well in butterfly gardens. The nectar-rich blooms attract many pollinators. For best effect, plant purple iris among other early flowering perennials and bulbs to provide a continuous food source for butterflies.

Caring for Purple Irises

To keep your purple irises looking their best, provide the following care:

  • Sunlight: Full sun is ideal, with at least 6 hours of direct sun per day
  • Soil: Well-drained soil enriched with compost
  • Water: Drought tolerant once established but appreciate weekly watering in dry periods
  • Fertilizer: Apply a balanced fertilizer in early spring before blooming
  • Pruning: Remove faded blooms to encourage reblooming. Clip back foliage after it dies back in fall.
  • Propagation: Can be divided every few years in summer by splitting thick rhizomes.

With proper growing conditions and care, the purple iris will continue providing gorgeous, regal color year after year.

Interesting Facts About Purple Irises

  • Purple irises are one of the most popular iris colors but are less common than the blue varieties.
  • They have been cultivated in gardens for centuries and were depicted in ancient Egyptian art.
  • Irises were used as a model plant by Gregor Mendel in his work on the principles of genetics due to their easily observable traits.
  • The iris flower is a symbol of wisdom, valor, and faith.
  • Purple iris flowers were once used to make blue and purple dyes.
  • Iris is named from the Greek word for rainbow due to the wide variety of flower colors.
  • Iris rhizomes can be dried and ground into a powder used for herbal remedies.
  • Irises belong to the Iridaceae family along with freesias, crocuses, and gladiolus.


With its regal elegance and saturated royal purple tones, the purple iris brings a striking pop of color to spring gardens. This classic perennial has been appreciated for centuries for its beauty and symbolism. With proper site selection and care, the purple iris will continue gracing gardens with its stunning floral displays.

So if you come across a tall iris in the deepest purple shades, you’ll know it’s likely the purple iris – one of the loveliest and most vivid of the iris family.